Frequency range generation

fft_frequencies	Alternative interface for np.fft.rfftfreq
cqt_frequencies	Compute the center frequencies of Constant-Q bins.
mel_frequencies	Compute an array of acoustic frequencies tuned to the mel scale.
tempo_frequencies	Compute the frequencies (in beats per minute) corresponding to an onset auto-correlation or tempogram matrix.
fourier_tempo_frequencies	Compute the frequencies (in beats per minute) corresponding to a Fourier tempogram matrix.