Detection of harmonics and rhythmic structure

[Brian Gygi <bgygi@xxxxxxxxxxx>]

Does anyone know some good algorithms for determining a) the presence or
absence of harmonics in a signal (non-speech), and b) whether the signal
is discrete or rhythmic (repetitive)?  I can imagine that these two
questions are related, one is in the frequency domain and one in the time
domain.  I have fooled around with autocorrelations, but want to be able
to extract a number that would capture the amount of either harmonic or
rhythmic structure in a signal.

PS if you have Matlab code, all the better.

Many thanks,

Brian Gygi
Indiana University