Tempo estimation.

Two methods are available:

• mus.tempo(..., 'Signal') uses the signal-based method estimation periodicities from the event detection curve, available in aud.tempo
• mus.tempo(..., 'Pattern') uses a more musicologically founded symbolic-based method based on pattern mining

This is a specialization of the aud.tempo method, adapted to the music domain.

For the periodicity estimation, instead of calling sig.autocor (if the method is 'Autocor') or aud.spectrum (if the method is 'Spectrum'), their specialization to music mus.autocor and mus.spectrum are called. The only reason is to use the 'Resonance' option (available in both mus.autocor and mus.spectrum operators) in order to weight the periodicity representation (autocorrelation function or spectrum distribution) with a resonance curve, which emphasizes the range of BPMs that correspond to pulsations in music.

mus.tempo(..., 'Resonance', r) controls the 'Resonance' option in the same way as in mus.autocor and mus.spectrum.

Same as in aud.tempo.

Same as in aud.tempo.