Music21 is a set of tools for helping scholars and other active listeners answer questions about music quickly and simply. If you’ve ever asked yourself a question like, “I wonder how often Bach does that” or “I wish I knew which band was the first to use these chords in this order,” or “I’ll bet we’d know more about Renaissance counterpoint (or Indian ragas or post-tonal pitch structures or the form of minuets) if I could write a program to automatically write more of them,” then music21 can help you with your work.

I worked with Professor Michael Cuthbert on Music21 as lead programmer from 2013 to 2014. Work included improvements to the project’s documentation building system, extending and optimizing its musical corpus-search tools, and building a framework for timespan-based harmonic reductions.

Source.

Documentation.