Useful Packages -- Installation Guide
Aubio/SoundAnalyse: Pitch Detection + Other Functionality
Use Aubio if you have a Mac and SoundAnalyse if you have Windows computer.
Aubio installation instructions are here.
SoundAnalyse instructions are here.
PyDub: Layering Sounds, Concatenating Sounds, Managing Volume & More!
Check out this awesome library that can be installed here.