Overview Ongaku is a method for creating playlists programmatically, using only the content of the song alone. It uses gammatone cepstral analysis to create unique matrices to represent each song. A gammatone cepstrum is similar to the more common spectra used for audio analysis. Instead of doing a Fourier transform, we do a reverse Fourier transform, and then apply a transformation according to the gammatone function. This function was designed to mimic the signals sent to the brain through the cochlear nerve, the nerve which connects the ear to the brain.