librosa : librosa is a python package for music and audio analysis. It provides the building blocks necessary to create music information retrieval systems.
ChipNomad : ChipNomad is a chiptune tracker for handheld consoles (Anbernic, TrimUI, Retroid, etc) and desktop platforms. It is heavily inspired by LSDJ and Dirty...
Overtone : Overtone is an open source audio environment designed to explore new musical ideas from synthesis and sampling to instrument building, live-coding and...
Catfish Smooth : This site is all about connections between music artists. In a sense, it is a music artist recommendation system but more. For each artist, you will s...
Sonerezh : A self-hosted, web-based application for stream your music, everywhere.
sonicsquirrel.net is a platform dedicated to netlabels and netaudio.
All music you find here is released under open licenses (mainly Creative Commons).