AAA is a great experimental web-instrument for crazy rhythms.
Spleeter is a free (donation possible) Music Source Separation utility that can split a song in to it’s separate parts.
This can be useful for restoring old vinyl recordings or cutting samples for remixing.
SPARTA is a collection of flexible VST audio plug-ins for spatial audio production, reproduction and visualisation, developed primarily by members of the Acoustics Lab at Aalto University, Finland.
Here’s Compass, one of the tools in the collection:
Visualize your collection of short audio samples in an interactive 2D point map using machine learning technology.
Analyze resulting groups and play your samples in a novel way using various innovative music composition modes.
Generate audio in your browser by certain rules with the WoframTones Generator. You can download results in several audio fromats and as well as MIDI files.