ChordEase
Improvise to music with difficult chords easily on any MIDI instrument
... rapid music theory calculations to ChordEase, you gain freedom to concentrate on other aspects of improvisation and performance, such as feel and aesthetics.
ChordEase is a translator that takes MIDI notes as input, and produces MIDI notes as output. The input notes are mapped to the current chord scale in various ways, so that the output notes fit the chord progression of a song. Multiple performers can play through a single instance of ChordEase, using any number of MIDI instruments.