Beats per minute from real-time audio input

Answer 1

First of all, what Hallgrim is producing is not the power spectral density function. Statistical periodicities in any signal can be brought out through an autocorrelation function. The fourier transform of the autocorrelation signal is the power spectral density. Dominant peaks in the PSD other than at 0 Hz will correspond to the effective periodicity in the signal (in Hz)...