I chaired a virtual conference! A how-to

Since late 2019, we have been organizing The 2020 Joint Conference on AI Music Creativity. This was going to be a union of two other ventures in similar engineering and artistic domains, namely the annual Music Metacreation workshop (MuMe), and the annual Computer Simulation of Musical Creativity conference. It was also going to be the celebratory kick-off event for my ERC project, MUSAiC: Music at the Frontiers of Artificial Creativity and Criticism (ERC-2019-COG No. 864189).

The joint conference was going to be three days featuring papers delivered at KTH, concerts at the Royal Conservatory (KMH), and social events throughout Stockholm, but the global pandemic made that impossible. So, we decided not to cancel, but go virtual. Now, how can we do that in an appealing and accessible manner? It turned out not to be too difficult, quite inexpensive, and to have several advantages.

In April, I reviewed several helpful resources on virtual conferences. Richard Parncutt’s “Virtual socializing at academic conferences” is excellent, and motivated me to spread several events throughout the day (CEST) to meet a number of time-zones. The ACM also has a great guide on virtual conference best practices. See in particular section 2.5, “Carving out mental space”, motivating short virtual sessions. Also Sec 4.2.2 “Small Conference or Large Workshop” provides some helpful logistics for the size event I was organizing.

Due to a fantastic response in terms of paper submissions, and the interest of several invited speakers, we decided to spread the conference over an entire week. The final schedule features eight paper sessions (of 105 minutes each, plus 15 minutes extra to solve technical issues), nine spotlight talks of 30 minutes each (with Q&A), two hour-long keynotes (with Q&A), and four 90 minute panels (with Q&A). The first day features two tutorials, one of which is repeated to accommodate other time zones. There is also an online exhibition of selected musical works with pieces introduced by the artists in two separate sessions. Here’s the final schedule:

To reduce online fatigue, and accommodate several time zones, I spread the events as much as possible.

Now, how to do this in a virtual format? I followed some other virtual conferences to see how they worked. And I taught a class of 300 using zoom. This led me to several conclusions:

1. We should use zoom. It has excellent reliability and the “original sound” feature is a big plus. Furthermore, one can record sessions automatically, and even stream them.
2. Large zoom sessions can be unruly and insecure. It would be pandemonium trying to have a number of paper presentations with questions and answers. It would also make the recording of the presentations unpredictable. So, we should limit who uses zoom.
3. The events should be viewable by the general public, but people who register should have something extra in terms of the conference experience.

Here was plan A:

My computer in Stockholm hosts secured zoom sessions with presenters, panelists and session chairs. I stream these sessions to YouTube, which is then viewed by the public and conference registrants. In cases where video is provided by presenters in lieu of a live presentation (internet connectivity might be poor), I stream the videos using Open Broadcaster Studio (OBS, free!). Conference registrants have access to a slack workspace dedicated to the conference, which has channels dedicated to each event and each paper where questions can be asked and topics discussed.

If YouTube decided to restrict my streaming ability, e.g., detecting copyright protected material in the stream and shutting it down, then Plan B was this:

All registrants would pile into Zoom, all would be muted except for the speaker, and questions would be posed on the conference slack workspace.

A big risk with both of these plans is the degree to which they rely on “Bob’s computer”, its connection to the internet, and its operator. If the computer breaks, gets disconnected, or Bob gets COVID-19, everything could topple. So Plan C was to make everything asynchronous: authors post videos of their presentations to slack, which are then discussed in non-real-time. Fortunately, we never had to deviate from plan A.

One major benefit of Plan A is that YouTube automatically records streams, so we didn’t need to record zoom sessions and then upload. They would automatically appear in the conference YouTube channel. There is even some online editing functions within YouTube Studio that can be used to make changes. (There were some funny behaviors, however — for instance a two hour stream appearing as 5 minutes. This seemed to happen when I switched from streaming video via OBS to streaming from zoom or vice versa. To correct it, I had to download the recorded stream and then upload again.)

Another nice thing about streaming to YouTube is I could watch engagement. Below is a screen shot of the streaming view in YouTube Studio at the conclusion of a paper session.

A drawback to using YouTube is its availability in all parts of the world, e.g., China. There are other possibilities, but by the time we had realized YouTube is blocked in China, it was too late.

Running the conference on Bob’s computer looked like this:

A paper is being presented in zoom to the other authors and chair of the session. This is being streamed “Live” to YouTube, where there is about a 5-second delay. The conference Slack workspace is shown at left. (purple) The YouTube Studio page is behind in the browser. And the OBS software is shown behind at right. It was a crowded workspace, but by the end of the first day I had the mechanics down.

On Tuesday morning after a brisk bike ride to work, and 30 minutes before the first session, I opened my laptop and watched the screen go haywire. Panic ensued, and I raced through my department to find an external monitor. Thankfully, the computer was fine but its screen was not usable. After the morning session ended, I took the computer back home on a careful bike ride, and positioned it on my desk where it remained the rest of the week. I also prepared my wife’s laptop to become a backup in case mine died.

During the conference, I kept a log of useful observations and best practices.

• ASSIGN A CO-HOST for each and every zoom session. It was in the middle of a paper session that my zoom crashed. I restarted zoom, logged into the session, and noticed there were no interruptions because the co-host’s connection continued hosting the meeting as well as the live stream. (I hadn’t realized this great redundancy before. Good work zoom!)
• Create a backup YouTube channel for streaming in case the main one gets taken down. During the streaming of one of the invited talks, I noticed a copyright violation:

In this case it just meant restricted monetization — which we aren’t doing anyway. But perhaps several such violations would cause a shutdown.

• Have a totally different streaming option ready to go, e.g., Twitch.
• Beware that running a virtual conference can cause your hands to get sweaty. This can lead to all kinds of unintended pointing and clicking using a trackpad mouse. One time I meant to point and click something other than the “End Live Stream” button. The unanticipated superfluidity of the interaction almost caused disaster! So take care with every point and click.
• Some presenters might not have reliable connectivity. So in preparation, have them create and send a video of their presentation to use instead. Send it the day before because it takes time to download them!
• Start each live stream session with a one minute introduction video. This gives you time to check on the health of the stream and prepares the presenters to go live.
• Create a different slack channel for each paper. One colleague thought doing this was a disaster because it makes a real mess of the slack workspace; but it turned out to be a great way to organize things and facilitate discussions. Do this before people accept the slack invite, and make all such channels added by default.
• Use free tools wherever possible. Github pages worked exceptionally well for the website and keeping it up to date. OBS worked flawlessly. YouTube streaming had some quirks, but it worked great. Slack turned out to be great.
• Assign chairs for each session, and have them contact the participants with instructions about the presentation. Write a template email for the chairs to use for contacting authors and soliciting videos.
• Give registration cost waivers for all paper reviewers that deliver, as well as all invited speakers.
• When using EasyChair as the chair, DO NOT add conflicts of interest. Otherwise you cannot make assignments and decisions for papers hidden from your view.
• Here are some tasks to delegate to students helping:
• Confirmation of dates and times with all invited speakers and session chairs. Also, collecting biographies and abstracts from invited speakers. And sending connection details for presenting.
• Creation of calendar invites to all conference events and distribution to registrants. (Make this adaptable to any time zone.)
• Creation of slack workspace and its channels
• Using social media (e.g., tweets) to publicize events during the conference
• Updating the conference website with links to videos soon after each event ends, and adding relevant text to each video, including funding acknowledgments.

Reflecting a week after this event, I am totally satisfied with how things worked, and would happily do it again. Renting a presentation room, hiring A/V assistance, printing conference materials, and catering, would have required registration costs of about €200 pp for about 40 paying attendees. Then the cost of having nine in-person invited spotlight presentations, two keynotes, and two concerts, would have made that price rise far higher. Instead, we were able to do most of this (online exhibition instead of live-streamed concerts) at a very small registration fee of €25 pp. The remaining costs were covered by the ERC project MUSAiC: Music at the Frontiers of Artificial Creativity and Criticism (ERC-2019-COG No. 864189).

Also clear from the conference YouTube channel is that there has been continued viewing of the presentations:

We can see when the conference occurred, but there have been about 150 views each day since the conclusion.

Thinking of the future, I think hybrid conferences are the way forward. Having remote presentations opens up a lot of the world to attend and participate. It greatly reduces expense and the consumption of resources. Networking in person is of course one of the most important aspects of real-life conferences, but great impressions can be made just as well via remote presentations and discussing work in online forums. The next time I organize an in-person conference, it will certainly include remote presentations and attendance.

“Music from EDSAC” (circa 1960)

Today is the first day of my 5-year project MUSAiC – Music at the Frontiers of Artificial Creativity and Criticism (ERC-2019-COG No. 864189). To mark the occasion I am posting recordings of a unique music composition: “Music from EDSAC” (c. 1960). This is one of the first human-machine music collaborations, but very little is known about it.

I first learned about this work from a chapter in the 1970 book, The Computer and Music, H. B. Lincoln (ed.), (Cornell University Press). The chapter, “Music composed with computers – A historical survey”, is written by Lejaren A. Hiller, who in 1957 worked with the ILLIAC supercomputer to compose the string quartet, The Illiac Suite. In this chapter, Hiller refers to a technical report he wrote in 1961 about his trip to Europe to learn about the state of contemporary music there, and to discuss the state of contemporary music in America. The librarian of the University at Buffalo Music Library, where the Hiller estate is archived, helped me locate this technical report: “Report on Contemporary Experimental Music, 1961” (Tech. Report No. 4, 1962). At the very end (pg. 84-85), Hiller writes of meeting a Professor of economics at Cambridge University (UK) who is working on programming a computer to generate music:

Mr. D. G. Champernowne, Trinity College, Cambridge, is a member of the faculty of economics who has used the computer at Cambridge University for problems in economics. He has also become intrigued, as a side interest, in programming musical composition. In his spare time, he has developed two programs for musical composition that are quite sophisticated and effective within their sharply prescribed limitations. These are as follows:

(a) Synthesis of Victorian hymn tunes. After an inspection of typical hymn tunes, Champernowne developed a set of empirical rules for composition of such music. He then wrote a computer program that consists of four distinct parts: (1) The generation of random numbers. (2) The generation of the top melodic line. (3) The generation of harmonic support. (4) Printout in alphanumeric notation. He has provision for rhythmic variety, passing notes, neighbor notes, and appoggiaturas. Moreover, the program could also be used to harmonize given tunes, since part (2) of the program can be by-passed and independent melodic data could be used instead. Thus far, however, he can only generate one phrase at a time, so awkward transitions sometimes occurred between the end of the one phrase and the beginning of the next phrase. Mr. Champernowne gave me several representative examples of the computer output he obtains. These disclose that this programming has thus far been very successful in solving this highly restricted musical problem.

(b) Synthesis of Serial Music. Mr Champernowne has also written a program for the synthesis of a species of twelve-tone serial music in which a systematic permutation scheme permitted the production of a composition about 200 measures long. He applies some arbitrary rules that eliminate, I believe, certain dissonances. It is thus interesting to note that this music superficially, at least, bears a resemblance to that of Barbaud and Blanchard. This composition is scored for string quartet. Mr. Champernowne has promised to send us a copy of the score. It will be probably worthwhile to tape a performance of this music for documentation purposes.

Writing almost ten years later in his chapter for Lincoln’s book, Hiller echoes what he had written in his technical report, but adds that “Champernowne, apparently, has not yet written an article for publication describing his programming. This is too bad, since it would seem that what he did worked out quite successfully within the specified constraints on the compositional process.” He also writes that Champernowne:

… arranged a three-movement “composition” for string quartet out of these materials consisting of (a) a set of “Victorian [hymn] tunes,” (b) the serial piece that serves as a sort of middle-movement scherzo, and (c) a series of harmonization of well-known tunes like “Rule Britannia.” Because Champernowne was unable to induce a string quartet at Cambridge to play his music, we asked him to send us a set of performance parts from which we assembled a score and prepared a tape recording of a performance by a string quartet at the University of Illinois. I find sections of this Music from Edsac quite entertaining, particular the harmonizations in the last movement.

The score that Hiller assembled is in his estate at the University at Buffalo Music Library, but his recording is lost. So I obtained a copy of the score, and with permission from the Champernowne family hired a string quartet to perform and record “Music from EDSAC”. Below are the three movements.

A little extra information comes from Dr. Andrew Herbert (OBE, FREng) Chairman of Trustees, The National Museum of Computing, Manager,  The EDSAC Replica Project. Dr. Herbert has told me that the computer Champernowne used was actually the second version, EDSAC 2. “[The two versions] were quite distinct and very different in construction despite sharing a name.  The sort of computing required by Champernowne was beyond what the original EDSAC could have accomplished. His work on EDSAC 2 is consistent with the kind of algorithms that people working in the Cambridge Language Research Unit (CLRU) would have been familiar with and are in fact early examples of the kind of statistical machine learning which has lead the recent resurgence in AI.”

Gentilia Pop Kårfors, 1st violin
Kent Carlsson, 2nd violin
Per-Ola Claesson, violoncello
Sofia Winiarski, conductor

The First Machine Folk Music School!

I’m very excited to be offering the first “Machine Folk Music School” on Sep. 13 (15-16h CEST) as part of the 2020 Ars Electronica festival:

During this hour-long “school” (over zoom) I will teach participants a machine folk tune in the aural tradition. This involves me first performing the tune a few times through to give everyone a feeling for it. Then we work gradually phrase by phrase, playing slowly and with plenty of repetition. We link together the phrases to build up parts of the tune. Then we put all parts together and repeat the entire tune several times slowly. Finally, I discuss several possibilities for variation of the tune. Participants will also be given a short tunebook containing several other machine folk tunes.

Introducing Bosca Dubh!

I’ve been living with Bosca Dubh for a month now and learning about its unique personality. Bosca Dubh is the next generation of The Black Box, which is essentially a D/G diatonic accordion redesigned to allow traditional Irish ornamentation. Bosca Dubh began its life as a club accordion, apparently designed by Excelsior. There are no identification numbers anywhere on the box or inside. I contacted Excelsior for information about this box, but they have no idea about it other than it could be one of a few specimens of a test model. This makes it even more unique and mysterious.

Compared to The Black Box, Bosca Dubh has two more treble-side buttons (on the inner-most row), and four more bass-side buttons. Here’s the layout:

The green buttons are identical to those of The Black Box. The other buttons are new. Here are the ranges of the two boxes, also showing the rolls that are possible:

The range of Bosca Dubh is one semitone lower than The Black Box, and has the high f natural. Bosca Dubh also can do rolls on F3 and G3. Neither box allows a traditional-style roll on F4 — but a triplet suffices. Everything else is the same on the treble side.

The bass side of Bosca Dubh is expanded. Like The Black Box, all thirds are removed. But Bosca Dubh now has A and F# on the press, and F and C# on the draw. These add lovely color to tunes in the keys/modes common to Irish traditional dance music. The C# is useful for tunes in A, and the F# is useful for tunes in D. The F adds a nice modal flavor to tunes in G.

Like The Black Box, the Bosca Dubh has LMMMH reeds (L = octave below; M = middle; H = octave above); but it has more couplers. Here’s a picture of all the voicings available on Bosca Dubh. (The dots and their position denote which reeds are active.)

The coupler pressed is “ALL REEDS GO!”. One can also choose just L, or just M, or just H. Then there are four couplers that choose combinations of these. There are three couplers choosing combinations of the middle reeds — let’s call them Ml (middle low), Mm (middle middle), and Mh (middle high). “Traditional” Irish tuning makes the Mm reeds right on concert pitch and then the Ml and Mh are detuned relative to that by up to 15 cents, lower or higher, respectively. This makes a “wet” or warbly sound. (Some traditional players, like Jackie Daly, use very little to no detuning of these reeds.)

The Ml+Mm coupler selects the middle reeds located in a cassotto chamber. This is another unique aspect of Bosca Dubh over The Black Box. Cassotto makes for a very mellow sound. Here’s a picture of the treble side showing the reed batteries in the cassotto chamber (top):

The most odd feature of Bosca Dubh is the coupler isolating Ml+Mh. The expert that converted this accordion (Erik Simons, highly recommended!) believes this is a mistake of the manufacturer. I’ve never seen such a coupler before. BUT, I love the sound. I call it the “circus setting”. This “mistake” lends credence to the theory that this box was a test model.

Now for a demonstration of Bosca Dubh, including its “circus” setting:

How does Bosca Dubh compare with the typical B/C accordions played in Irish traditional music? Below are the ranges of Bosca Dubh compared with the standard B/C layout of the popular Paolo Soprani boxes:

We can see several things. Bosca Dubh doesn’t go as low as the B/C, but it does go higher. The longest chromatic run of notes on the B/C is two on the press and four on the draw; but on Bosca Dubh it is ten on the draw and five on the press (in the middle of the range). Each roll on the B/C can only be performed in one direction of the bellows, but on Bosca Dubh many rolls can be performed in both directions. The only rolls Bosca Dubh cannot perform that the B/C can are E3 and F4. The B/C cannot perform rolls on C# or F#.

Another typical system in Irish traditional accordion is C#/D, which is just tuned a semitone higher than the B/C. Thus it shares much of the same characteristics:

As for the B/C, Bosca Dubh doesn’t go as low as the C#/D. As for the B/C, the longest chromatic run of notes on the C#/D is two on the press and four on the draw. Each roll on the C#/D can only be performed in one direction of the bellows, but on Bosca Dubh many rolls can be performed in both directions. Unlike the B/C system, the C#/D can perform rolls on C# and F#, but not on F natural.

A big advantage of Bosca Dubh and The Black Box over B/C and C#/D accordions is the expanded harmonic possibilities on the treble side. Many more note combinations are possible, which makes them versatile instruments for accompaniment. Here’s a table showing several of the chords that can be played on the treble side: “M” is major, “m” is minor, “M7” is major with raised 7th, and “dim” is minor with diminished fifth.

For a given root, the major 7 chord resolves to the IV, while the diminished chord resolves to the V. So in Irish traditional music, several of these wouldn’t be useful, e.g., C#dim, Adim, B7 and Bdim. More often, however, intervals of octaves, fifths and fourths are used on Irish accordion.

In conclusion, the expanded bass on the Bosca Dubh is the biggest and most useful change from The Black Box. The two additional buttons on the treble side aren’t really that useful. The cassotto on Bosca Dubh is very nice, as is the organ/melodeon sound. The circus setting is a fun unique one. If I were to look toward the next design, I might trade some of the high notes for the low ones available on B/C and C#/D, e.g., remove everything from the Eb6 up and add in the B2 to D3. This however would make the box have a sixth button start, shifting my hand position down one, which might actually be beneficial ergonomically.

Coming soon …

At left is The Black Box. It has been perfect! My design of the keyboard has worked out so well. The left hand side, however, is a bit limited. I really miss the F/F# that is on The Mean Green Machine Folk Machine (now sold to a new loving family). So, enter the box at right (so far unnamed). The treble side has two more buttons, but the bass side has four. It’s now in the shop being converted to my new design! Details coming soon…

An analysis of the 365 double jigs in O’Neill’s, pt. 10

This is part 10 of my live blogging analysis of the 365 double jigs in O’Neill’s 1001. In the last part, I revise and tune the procedure by which I extract time-pitch series from the collection, and then analyze several examples. The part before that reviews where I have been.

While reading O’Neill’s “Irish minstrels and musicians: with numerous dissertations on related subjects” (1918), I found the following quoted from “A History of Music in England” by English composer Earnest Walker (1907). I believe it really encapsulates  implicit and explicit properties of Irish traditional music:

Few musicians have been found to question the assertion that Irish folk-music is, on the whole, the finest that exists; it ranges with wonderful ease over the whole gamut of human emotion from the cradle to the battlefield, and is unsurpassed in poetical and artistic charm. If musical composition meant nothing more than tunes sixteen bars long, Ireland could claim some of the very greatest composers that have ever lived; for in their miniature form the best Irish folk-tunes are gems of absolutely flawless lustre, and though of course some of them are relatively undistinctive, it is very rare to meet with one entirely lacking in character. (pg. 335)

I wonder if the convention of Irish tunes being sixteen bars long relates to physical limits of human memory, and the aural transmission of tunes?

Anyhow, in this part I investigate extracting a feature complementary to time-pitch series: one describing rhythmic aspects of a transcription. Let’s consider jig #201 (“Biddy’s wedding”):

We see notes of four different durations. From shortest to longest: semiquaver, quaver, dotted quaver, and crotchet. In the entire collection, there are notes of three other durations: triplet semiquaver, triplet quaver, and dotted crotchet. One way to describe the rhythm of any transcription in this collection is by expressing it as a sequence of encoded durations where. Let’s try a simple one: 1 means a triplet semiquaver, 2 means a semiquaver, …, and 7 means a dotted crotchet. So the series describing “Biddy’s wedding” starts: 5, 2, 6, 4, 4, 4, 4, 4, 4, …

Even better would be an encoding that directly describes time. Dividing each quaver of a 6/8 measure into 6 segments (Fs = 6 segments/quaver) results in a triplet semiquaver lasting 2 segments, a semiquaver lasting 3, a triplet quaver lasting 4, a quaver lasting 6, a dotted quaver lasting 9, a crotchet lasting 12, and a dotted crotchet lasting 18. Hence, such a series extracted from “Biddy’s wedding” starts: 9, 3, 12, 6, 6, 6, 6, 6, 6, … In this way we can easily isolate measures, and accumulate the values of the series to create a series of onset times, i.e., for “Biddy’s wedding”: 0, 9, 12, 24, 30, 36, 42, 48, 52, 58, … Call this indexed series $O$.

The problem with both of these approaches is that the length of a series is equal to the number of notes in a transcription. I want a feature that facilitates the comparison of transcriptions and their parts. This can be done by making all series the same length. Hence, I create the onset-time series of length Fs*6*8 = 288 according to the following:

$o = 1_{O}(n) : n \in [1,288]$

using the indicator function. So the onset-time series is just a series of 288 ones and zeros. For “Biddy’s wedding” the onset-time series looks like:

Each spike shows an onset. Those of the A part are shown in blue and orange, and those of the B part are shown in green and red. It’s hard to differentiate between the series, so let’s view these in an alternative way:

Series 1 and 2 are from part A and 3 and 4 are from part B. Time in each sequence is going along the x-axis, six steps for each quaver, six quavers for each measure, and 8 measures for each series. Series-time in each tune is going along the y-axis, where each part contributes two series since there are repetitions. There is a change in pixel value where an onset occurs.

Let’s have a look at some others. Below is the onset-time series for jig #24 (“The maid at the well”):

This shows each part is built from two measures with the same rhythm: 10 quavers and a crotchet. Here’s the dots:

The onset-time series below shows a sequence of 22 quavers and a crotchet:

This is from jig #32 (“The basket of Turf”):

And here we see quavers all the way:

Those are the onset-time series of jig #125 (“Wasn’t she fond of me?”):

The pickup doesn’t appear in the onset-time series (or any of the other series) because it does not occur in any repetitions. Its existence is seen in the time-interval series, however (start of blue line):

Here’s a strange pattern of onset times:

That’s from jig #357 (“The Hibernian jig”). The dots show what is going on:

For some reason, O’Neill has explicitly notated an exaggerated jig rhythm. The transcription could also be notated with straight quavers and interpreted in the manner above.

How many jigs in this collection have such exaggerated jig rhythms? Only 14 of the 365 notate the dotted quaver semiquaver rhythm at least 8 times: #8, 76, 101, 148, 181, 201, 212, 222, 229, 256, 257, 294, 322, and 357. Jig #101 (“The idle road”) is one of these I looked at in part 5, which is played by Joe Burke with an unbroken rhythm.

Here’s another interesting one:

This is of jig #95 (“The sheep on the mountains”). This is the only jig in the collection with a structure different from all the others: ABAB, where each part is 16 measures long:

Here’s another, of jig #200 (“Daniel of the sun”):

The B part of this tunes looks to be more syncopated than the other two parts. The transcription shows plenty of broken rhythms, including Scotch snaps, in these parts:

The below are the onset-time series for jig #226 (“Tim Hogan’s jig”):

It appears that the parts become more and more dense with notes. Here’s the transcription:

We see the crotchets of the A part are notated as trilled, or rolled. The B part features mostly quavers. Then the C part has semiquaver passing tones.

Here’s another unusual one:

That is for jig #361 (“The Drogheda weavers”). There appears to be a flourish of notes starting each four measure section of the B part. Here’s the transcription showing what is happening in that part.

By way of summary, let’s look at the ways in which we can describe the characteristics of a give transcription from O’Neill’s 1001. Let’s consider one of my favorite jigs, “Scatter the Mud” (#187). Here’s the ABC notation:

M:6/8
K:Am
d|eAA B>(cB/A/)|eAA ABd|eAA B>(cB/A/)|dBG GBd|
eAA B>(cB/A/)|eAA AGE|GAB Bge|dBA A2:|
|:d|eaa egg|dBA ABd|eaa egg|dBG GBd|
ea^f ({a}g2)e|dBA AGE|GAB Bge|dBA A2:|


And here’s the dots:

Here’s the onset time series of “Scatter the Mud”:

Here’s the time-pitch series:

As is convention, the B part goes higher in pitch than the A part. And the two parts echo each other in the middle and end. Here’s the time-interval series:

And finally, here’s the circular autocorrelation of the time-interval series:

We see the A part is has high self similarity at lags of one measure, and the greatest value at four measures (other than zero lag). The B part has more self-similarity with a lag of  two measures.

In the next part, I think I will look at clustering transcriptions according to their onset time series.

Seán Ó Riada is one of the most important Irish composers of the 20th century, and a key figure in the revival of Irish traditional music. In 1960, he assembled a group of traditional Irish musicians, named “Ceoltóirí Chualann“, to present traditional music in a classical music concert setting. They gave several influential concerts, and the group is considered a precursor to one of the greatest modern Irish music groups, The Chieftains, who have had 18 Grammy Award nominations.

In 1963, Ó Riada recorded a series for Raidió Éireann called “Our Musical Heritage”, in which he introduces and discusses Irish traditional music and its elements. In one of these he discussed the button accordion. I can’t find any transcription of his commentary online, but I love it so much I will transcribe it here.

Ó Riada prefaces his commentary with the following:

First of all, it needs to be emphasized over and over again, that Irish traditional instrumental music is a very close relation of Irish vocal music; that is, sean-nós [old-style] singing. The instruments which suit Irish music best are therefore those that most closely approach the personal expression of the human voice.

The fiddle is ideal. The player is in contact – in complete contact – with his instrument. The notes do not exist until he makes them; and his tone is a completely individual thing, differing from another fiddle player’s tone as much as one voice differs from another. This is also true to varying extents of the uilleann pipes, the flute, and the whistle.

Irish music is entirely a matter of solo expression, and not of group activity. It is the direct expression of the individual musician or singer. It is again very much a matter of personality. Whether that personality exists or not outside the music. That is to say, a singer, a piper, or a fiddler may be quite an unpleasant person when not performing but when performing it is his music personality which counts, which impresses us – the direct expression of his musical personality. Everything that comes in the way of that direct expression beclouds and confuses it.

Now, the most direct means of expression in music in the human voice. Next, in varying degrees, as I said, come the uilleann pipes, fiddle, flute, and whistle. In each of these the player makes the notes himself. He is in control. The notes do not exist  until he makes them. The fiddle player and the piper make the notes with their hands. The flute player and whistle player, with their mouth and hands. They are at all times directly in contact with the actual notes they make. And as a result, they are the masters of the notes. They control them. Varying their loudness and their softness. Their tone quality, and even their intonation.

This, the accordion player cannot do. He does not make the notes – they are already there before him. Ready to sound at the pressing of a button, produced in an almost entirely mechanical fashion. Thus, he has not the control over his instrument that the others have. He has only to press a button and pull or push the bellows and the note sounds for him. The tone and even the intonation have already been decided for him by the maker. Because of this, individual musical expression becomes extremely difficult, if not impossible for him. For this reason, if not for any other, the use of the accordion as a solo instrument in Irish traditional music is to be greatly deplored.

Most accordion players are so hampered by their choice of instrument as to be unable to produce anything but a faint, wheezy imitation of what Irish music should be. And the most unfortunate part of it is, that this instrument, designed by foreigners for the use of peasants who had neither the time, inclination or application to learn a more worthy instrument – this instrument is not just losing favor, but gaining vast popularity throughout the country. The reason for this is mainly, I think, the laziness which afflicts us as a nation at the moment.

We would all like to be musicians, but we don’t want to take the trouble. It is easier to play notes which are already made for us, than to make our own notes. Accordions, bigger and better accordions, and eventually the greatest abomination of all – the piano accordion – nothing could be farther from the spirit of Irish traditional music.

However, I’m afraid this has been a rather long digression. As I said, very few accordion players in this country can surmount the difficulties inherent in their instrument. Most feel on the other hand that something must be done to enable them to produce more expression on the accordion. As this can’t be done by means of varying the tone, and so forth, they have turned to the one thing which it is possible to exploit, namely ornamentation. And it is precisely with regard to ornamentation that accordion players have committed their greatest crimes. In recent years, a technique and style of chromatic ornamentation, utterly alien from the spirit of Irish music, has grown up.

But before I describe it, let me mention briefly the two basic principles of ornamentation. And incidentally, I did not invent these principles. These principles are based on practice – the practice of the best players under the best circumstances. They are not invented principles, they are merely observed principles.

And the first is: generally speaking, no ornament should go outside the mode of the song or tune in which it occurs. And the second is: no ornament should, by its position, draw attention to an irrelevant note in the phrase in which it occurs. As by doing so it destroys the basic shape of the phrase.

At this point, Ó Riada uses the piano to illustrate permissible and impermissible ornamentation. He then caricatures the chromatic ornamentation he was hearing performed by the very influential Irish accordion players of the time, i.e., Paddy O’Brien and Joe Burke (though he does not name names). These players “throw in as many semitones” as they can. Eventually, Ó Riada renders a simple tonal phrase in the key of G into an unrecognizable chromatic mess [QED]. He continues:

The worst feature of it, to my mind, is not so much the incidental semitones, as is the dreadful habit they’ve got of using the downward semitone-inflected mordent, where you begin on a note, go to the semitone below and back to the note. Funnily enough, it is far more common than the upward-inflected mordent, where you begin on the note and go to the next note above it.

So the main downfall of the present day accordion players is the downward-semitone inflected mordent. This kind of thing is of course complete and utter rubbish; and it is up to the musical public to make their disapproval felt.

As I said, there are very few accordion players in this country who can sufficiently overcome the disabilities and limitations of their instrument. So as to make what they play sound like Irish music. But one of these few players is Sonny Brogan of Dublin. He is a man who understands the limitations of his instrument, but who strives to counteract these not in a mishmash of wrongly placed ornamentation, but by emphasizing the most traditional elements in the tunes he plays. His ornamentation is simple usually confined to the single cut, or grace note, and the roll.

Ó Riada then plays recordings of Brogan playing the reels “Repeal of the Union”, “The hut in the bog” and “Gordon’s reel”, and finally the jig “Morrison’s”. He highlights Brogan’s use of variation.

To sum up then, the accordion has been played in this country – the two row button accordion, that is – for upwards of 40 years. And I’m afraid that it has come to stay. However, while I have emphasized its unsuitability for solo playing, it can be a most  useful instrument in a band – something about which I am going talk next week. As a proverb says, it’s an ill wind. If only most Irish accordion players would try to fit in with the tradition instead of flying in the face of it, something would be achieved.

And one last word about the accordion: I wish, and indeed I wish again, that all Irish accordion players would drown, muffle, destroy, subdue or in some other fashion, silence the bass of their instrument. I haven’t yet heard an accordion player who knew the right bass to play, and it’s far better to play no bass anyway. It only interferes with the tune and confuses it.

Ó Riada continues his programme by talking about the concertina, which he finds to be superior to the accordion for Irish traditional music (e.g., “it’s not one tenth as unwieldy as the accordion”), and laments its decline.

One repercussion of my research in applying AI to model transcriptions of Irish traditional dance music is that I have become a dedicated student of Irish accordion. But I take no offense to any of Ó Riada’s verdicts and criticisms. Some of them are clearly laughable, such as peasants too busy to learn a “more worthy” instrument, and his nation “afflicted” with laziness. Some are uncomfortably nationalistic, such as those instrument-making foreigners. Some are contradictory, such as when he lauds the concertina over the accordion while overlooking that concertinas and accordions were being made by the same foreigners, and that the concertina involves the exact same mechanics as the accordion. And some are curiously unfair, such as overlooking the great expression that can be accomplished with the bellows. At least the accordion can produce dynamics like the human voice, which is not possible on the uilleann pipes – a more “worthy” instrument for Ó Riada. I am however persuaded by his opinion on some approaches to  playing bass on the accordion. I think sparse is the best approach, and only if it fits harmonically.

Ó Riada’s main argument with the fashion of accordion playing at his time is focused on music theory: the “great crime” of downward semitone-inflected mordents. Therein lies Ó Riada’s great crime: using a music theory that is in and of itself foreign to Irish traditional music to castigate contemporary practices of Irish traditional musicians.

I see Ó Riada’s programme on the accordion as a wonderful time capsule from just before Irish traditional music began its transformation into a major economic resource for Ireland – something that is due in large part to Ó Riada. The accordion would soon become a principal instrument of Irish traditional music. Controversy around the accordion would be replaced with controversy around the guitar and the bodhran, group playing, and eventually commercialization – the latter of which was as vigorously denounced by more modern “gate keepers” as Ó Riada denounces the accordion, e.g., Tony MacMahon in his wonderful 1996 essay, “The Language of Passion“.

An analysis of the 365 double jigs in O’Neill’s, pt. 9

This is part 9 of my live blogging analysis of the 365 double jigs in O’Neill’s 1001. The last part reviews where I have been. In this part I look at the time-pitch series of the collection. I create these series by single nearest neighbor regression on tuples of pitch and time observations extracted from a transcription. As an example, here is jig #201 (“Biddy’s wedding”):

Its four pitch-time series appear like so:

This feature has a clear relationship to the transcription because it shows which pitch occurs at what time over 8-measure segments. I can extract a time-interval series from these series by moving stepwise along time and finding and holding subsequent differences. The time-interval series for “Biddy’s wedding” appears like so:

The step of 5 semitones for series 2-4 come from the G pitch at the end of each line. I am making the first interval of the first series always be zero.

Here is the transcription I found at the center of a multidimensional scaling of the collection of transcriptions, jig #134 (“Young Tim Murphy”):

And here is its time-pitch series:

The two parts appear quite different save for the last two measures. Here is the time-interval series I extract from this:

In terms of intervals, we see the two parts are similar in measure 4 as well.

One difference between the two jigs above is the anacrusis. This in effect shifts to the right each series of #134 with respect to those of #201. If I am comparing only the series extracted from one transcription, there’s no problem since they all have the same shift. But if I want to compare series across transcriptions, some with an anacrusis and others without, I need to account for the shifts, i.e., align the measures. This will be important to consider when looking at tunes as sequences of measures.

The music21 library provides an easy way to detect an anacrusis, so I have rewritten my feature extraction code such that all series are aligned by measure. Let’s continue looking at the time-pitch series of the collection.

The dots of jig #17 (“The eavesdropper”) are:

and results in the following time-pitch series:

Note that middle C is pitch 60, but I have transposed all jigs in this collection to have a root of C. Here is the time-interval series I extract from the time-pitch series:

One major difference in extracting the time-interval series from the time-pitch series as to how I was doing it before is that this new approach considers repeated pitches as one. So the run of B quavers in the first measure are grouped together in an interval of 4 semitones over 3 quavers. I think this is preferable from the standpoint of considering melody. Playing 3 quavers in place of a dotted crotchet does not change the melody other than its rhythmic characteristic.

(This motivates extracting a “time-duration” series from a transcription to describes its rhythmic characteristics. Instead looking at what pitch is playing when, look at what duration is playing when. Ignoring graces, rolls, and trills, the collection has only pitches of seven durations. From shortest to longest these are triplet semiquaver, semiquaver, triplet quaver, quaver, dotted quaver, crotchet, and dotted crotchet. I will explore this additional feature at a later time… but keep in mind that the features I am extracting are not exemplary of how these tunes are experienced in performance. These are just the bones of the tune as it was in someone’s hand in the early 20th century, without any meat, flesh or movement.)

In the time-pitch series for “The eavesdropper”, we also see how its B part departs from the A part by going higher in pitch, and then descends back to join it. A typical feature of two-part jigs in this collection is that the B part sits above the A part in pitch. To get an idea of how typical it is, let us sum the set of differences between time-pitch series 3 and 1, and of 4 and 2 for each two-part jig in the collection (N=291), and make a histogram of them:

A positive difference means part B of a tune spends more time at pitches higher than part A. I find 268 of the 291 two-part jigs (>92%) have a positive difference. The two-part jig that has the largest difference is #190 (“O’Mahony’s frolics”):

Here are its time-pitch series:

Notice how the first ending of the B part stays high, and the second ending takes the melody down back home.

Of the 23 two-part jigs with a negative difference, the most negative one is #57 (“The blazing turf fire”):

Here are its time-pitch series:

What happens in jigs with more than two parts? Here’s the time-pitch series of the four-part jig #286 (“Strop the razor (2nd setting)”):

We see the melody goes highest in penultimate part (series 5&6). we see the same in the three-part jig #320 (“The piper’s welcome”):

This is not the case in the three-part jig #344 (“The stolen purse”):

Another interesting feature I see in some tunes is contrary motion of the parts, e.g., jig #223 (“The rambler from Clare”):

The time-pitch series show this “mirror image” effect:

This is probably not an accidental feature, but done consciously or planned in composition. Jig #237 (“The Fardown farmer”) has the same kind of construction:

Here are its dots

The A part of this jig and the A part of “The rambler from Clare” are so similar it makes me wonder if the Fardown farmer was the that rambler from Clare

Other tunes have similar intervalic motion in their parts. Here’s jig #249 (“The flitch of Bacon”):

And here’s the corresponding time-pitch series

This also shows how I disregard rests in my extraction of the time-pitch series, just extending the duration of the pitch preceding it.

An analysis of the 365 double jigs in O’Neill’s, pt. 8

This is part 8 of my live blogging analysis of the 365 double jigs in O’Neill’s 1001. It’s time for a breather. Let’s have a review!

1. Part 1 discusses O’Neill’s collection of jigs, and how I have normalized the transcriptions expressed with ABC notation. I use the normalized Damerau-Levenshtein distance (DL distance) to compare the transcriptions as strings, which locates some “duplicates” and variations, as well as several errors in the transcriptions. I find that the normalized DL distance provides sensible results.
2. Part 2 looks at the similarity matrix created from the normalized DL distance between all pairs of transcriptions. I analyze some of the pairs that have very large distances. I also perform some multidimensional scaling of the collection with the similarity matrix and look at the transcriptions that are at the center of the cluster. Finally, I observe that applying string edit distances to ABC notation is musically naive, e.g., “DEFG2G” in C major and “DEFG2G” in C minor are different.
3. Part 3 reduces the transcriptions to sequences of measure tokens and looks at the different measure structures present in the collection. This uncovers more errors in the transcriptions, and leads to further normalization of the collection. Performing multidimensional scaling on the reduced sequences creates sensible clusters.
4. Part 4 converts each transcription into “time-interval series”, which describes the intervalic “profile” of the melody. I explore other series derived from this representation by integration, circular autocorrelation, and marginalization (integrating out time). It is clear that the transcriptions in this collection have a well-defined structure having sections of eight measures, which motivates comparisons of features extracted from these sections, and smaller subsections of 1, 2 and 4 measures.
5. Part 5 inspects several 8-measure time-interval series in the collection, and gives a broad sense of the intervalic structures of the collection. I also find more transcription errors. I look at transcriptions with time-interval series that have specific statistical characteristics. I also look at the collection as a whole and find some interesting trends, e.g., time spent at pitches arrived to by a perfect fourth up is longer than vice versa.
6. Part 6 looks at clustering the 1,712 8-measure time-interval series of the collection. I analyze the centroids, and the distributions of distances to these. I transform some centroids to transcription sequences, which do not resemble any of the tunes in the collection. I also begin to inspect the circular autocorrelation of the time-interval series, which I believe are more indicative of the melodic structure in a transcription, e.g., revealing repetitions within a series.
7. Part 7 looks at clustering the 1,712 circular autocorrelations of the 8-measure time-interval series. I analyze the centroids, which make more musical sense to me than the centroids created from the time-interval series. The structure of a melody is more apparent in these representations, but there are some details that need to be worked out.
8. Part 8 reviews where we have been, and some questions that remain open. I also look at the sensitivity of a time-pitch series to subtle transformations of the originating transcription.

I have a growing list of open questions:

1. A multidimensional scaling of the transcriptions according to their normalized DL distances places a few transcriptions closest to the center of the cluster: jigs #134 (“Young Tim Murphy”) and #296 (“Barney O’Neill”). How stable is that position? What is the significance of those transcriptions in that position? What does that position mean musically speaking, if anything? (Perhaps this is not worth investigating given the lack of musical meaning of a string edit distance between ABC transcriptions.)
2. A number of features have been proposed that express the musical content of a transcription in eight-measure sections: 1) (mean-centered) time-interval series; 2)  (normalized) circular autocorrelation of time-interval series; 3) integral of time-interval series; 4) time-marginalization of time-interval series; 5) histogram of time-marginalization of time-interval series. What about expressing the normalized melody (transposed to root C) as a time-pitch series? What is the musical significance of each of these features?
3. K-means clustering of the circular autocorrelation of time-interval series shows some sensible results, e.g., finding eight-measure series that are structurally similar. What changes when we perform K-mean clustering on normalized circular autocorrelations (that is, dividing each by the value at zero lag)?
4. If we break the time-interval series into units of one-measure duration, how many unique units are there? How do they relate? Are there “prototype” measures? Might we see each eight-measure series as a concatenation of these “codebook” units?
5. My explorations so far show how we can analyze a collection of transcriptions. Can these approaches be used to compare two collections of transcriptions? Say,  O’Neill’s collection with another collection of supposed jigs, say computer-generated, hmm? Hmmmm?

Near the conclusion of the last part, I noticed something that needs more thought. Let’s look at jig #201 (“Biddy’s Wedding”):

This is a very simple tune. Harmonically both parts are: I-I-I-V-I-I-IV-V. The A part is built from two-measure bits like so: abac. The B part is just a variation: a’b’a’c. “Filling in”  crotchet-quaver pairs with passing tones or chord tones, or removing those, do not change the melody. But the time-interval series show these as major changes:

The c part in measures 7&8 is clearly identical. The b and b’ parts appear quite close as well, except for the big long-duration jump of 7 semitones in b’. However, the relationship between the a and a’ parts is not clear. Performing a correlation of these parts of the series would involve a multiplication of a string of zeros, which would reduce its value.

The circular autocorrelation of these time-interval series of this tune suggests its both parts are not closely related:

From looking at the transcription, I expect both parts of this tune to produce large peaks at a lag of 2 and 4 measures, which we see. But the half-measure peaks in the B part (lines 3&4) are curious, as are the small peaks for the A part at some other fraction of  a measure.

Let’s do an experiment to see how robust these features are. I will slightly modify the transcription as below and recompute the time-interval series and its circular autocorrelation:I have added an anacrusis to each part, and have filled in the crotchet-quaver pairs. Here’s the time-interval series for these parts:

The circular autocorrelation of these are:

The differences with the original features do not appear to be that great, which is a good sign. I still see that curious structure in the A part.

If we make the arpeggiation of I in measures 2&6 of the A part go downward like so: the circular autocorrelation of the time-interval series become more similar:

I don’t think such a minor change to the transcription should result in a major change of high-level features extracted from it. This points to the fact that the time-interval series are too detailed to make meaningful comparisons of melodic structure.

I think I have to return to basics and look at representing the melody as a time-pitch series, and how this might be transformed into a feature that more clearly expresses  structure.

An analysis of the 365 double jigs in O’Neill’s, pt. 7

This is part 7 of my live blogging analysis of of the 365 double jigs in O’Neill’s 1001. Part 1 is here, part 2 is here, part 3 is here, part 4 is here, part 5 is here, and here is part 6.

Now let us look at the results of k-mean clustering of the circular autocorrelations of the 1,712 time-interval series. I start with a single cluster and look at the centroid and the distribution of distances to it. Here is the 145-dimensional centroid:

That looks pretty good. The high value at zero lag suggests this is a sequence with some large time-intervals. The peak at a lag of four suggests that half of the series strongly resembles the other half. The peak at two suggests that the series is built from a two-measure bit. And so on. Let’s look at the distribution of Euclidean distances to this centroid:

The median of this distribution is around a distance of 104. The largest Euclidean distance we see is about 996, and the smallest is 65. The series furthest from this centroid is in jig #257 (“The Morgan Rattler”), which we keep seeing is a very unique jig in this collection. The series closest to this centroid comes from jig #155 (“Jackson’s rambles”). Here’s its circular autocorrelation:

It looks like part A of this tune contributes the matching series. The dots below show this part has a four-measure structure, and some repetition of intervals at the two-measure level:

Here’re the centroids coming from K-means with two clusters:

And here are the distance distributions:

There are 1479 series in cluster 2, but only 233 in cluster 1. The Euclidean distance between the two centroids is about 200.

Let’s try four clusters. Here are the centroids (x-offset is just for display):

Now we can see centroid 1 (population is 209) has to do with time-interval series with similarities at the half-measure-level, centroid 4 (pop. = 98) has to do with time-interval series with similarities at the measure-level, centroid 2 (pop. = 202) has to do with time-interval series with similarities at the two-measure-level, and centroid 3 (pop. = 1102) is perhaps something to do with similarities at the four-measure level.

Here’s eight centroids:

And the distances within each cluster.

Cluster 8 is the most populated, with 697 series; but cluster 6 has only 4. Let me guess: those come from “The Morgan Rattler”… Indeed, I see series from #257. But also #154 (“The Antrim lasses”):Here’s the autocorrelation of its time-interval series:

The B part of this tune shows the same structure we see in centroid 6.

There are 48 series in the cluster described by centroid 5 coming from 22 jigs: #6, 18, 23, 30, 56, 71, 82, 117, 125, 126, 127, 172, 178, 183, 186, 201, 204, 258, 274, 287, 291, 343. These should have sequences with repetition at the half measure. Let’s look at two. Jig #18 (“Saddle the pony”):and jig #201 (“Biddy’s wedding”):Looking at the autocorrelation of their time-interval series shows their similarity in this domain (the first is “Saddle the pony”):

Even the other two parts look related! So time-intervalically speaking, we can see why these sections would be grouped together. However, the melodies of these jigs are not very similar.

I have searched the web for people playing these tunes, but there appear to be none! All the performances I can find of “Saddle the pony” are actually the jigs “The Priest’s Leap” (#59) and “The Draught of Ale” (#156) in O’Neill’s 1001 (identical tunes). And “Biddy’s wedding” doesn’t appear to have been recorded anywhere. So learn to play them I have:

Here’s one time through “Saddle the pony” in O’Neill’s 1001 on The Black Box:

Here’s one time through “Biddy’s wedding” from O’Neill’s 1001 (but played in G):

And now I find something curious! “Saddle the pony” appears in O’Neill’s 1850 as two settings, both in A major. The second setting is the one appearing in O’Neill’s 1001, but  with a dropped seventh (A mixolydian):

Why didn’t O’Neill include both settings in his 1001? And where did the G sharp go? I do think the flattened seventh sounds more Irish.

Update: 20200402

My teacher Paudie O’Connor says the G sharps might occur in Donegal, but that the 1001 version plays well as written. There is a four-part jig called “Langstrom’s Pony” that has as its first two parts this version. Here’s De Danann playing the tune: