From: S. Park, J. Park, and K. Sim, “Optimization system of musical expression for the music genre classification,” in Proc. Int. Conf. Control, Auto. Syst., pp. 1644-1648, Oct. 2011.
In this simulation of William Martin Joel ‘Piano Man’ song 29 other songs were a bit of an experiment to extract. Using a filter with frequency band limited reason to put the instrument used in music to have its own frequency band can be. Person’s voice is also statistically 200Hz-3kHz. In this paper, to minimize the voice of a man crushed because his voice had taken to preserve some of the background music focused.
Emphasis is mine. Poor William!