audio - Chord detection algorithms?

Question

I am developing software that depends on musical chords detection. I know some algorithms for pitch detection, with techniques based on cepstral analysis or autocorrelation, but they are mainly focused on monophonic material recognition. But I need to work with some polyphonic recognition, that is, multiple pitches at the same time, like in a chord; does anyone know some good studies or solutions on that matter?

I am currently developing some algorithms based on the FFT, but if anyone has an idea on some algorithms or techniques that I can use, it would be of great help.

Answer 1

This is quite a good Open Source Project: https://patterns.enm.bris.ac.uk/hpa-software-package

It detects chords based on a chromagram - a good solution, breaks down a window of the whole spectrum onto an array of pitch classes (size: 12) with float values. Then, chords can be detected by a Hidden Markov Model.

.. should provide you with everything you need. :)