1. A method for automatically forming a feature set describing an electronic signal representing a piece of music, the method comprising: (a) receiving the electronic signal into a computing device; (b) performing a wavelet decomposition of the electronic signal to obtain a plurality of wavelet coefficients in a plurality of subbands; (c) forming a histogram of the wavelet coefficients in each of the subbands; (d) calculating an average, variance and skewness of each of the histograms; (e) calculating a subband energy of each of the histograms; and (f) forming the feature set such that the feature set comprises the average, variance, skewness, and subband energy of at least some of the subbands.