Magenta Studio

Magenta Studio is a free set of MIDI tools from Google's Magenta research team, packaged as Max for Live devices for Ableton Live. It can continue a melody, generate new drum patterns or melodies, interpolate between two clips, humanize timing and add drums to a groove. Version 2.0 moved everything inside Ableton for stability, and the models run offline. It's more of a creative sketchpad than a production tool, and Magenta's newer research, such as its real-time music models, lives on its site as separate demos.