It's a different, more intuitive music keyboard, combined with a chorder. It supports over 50 different grids, 14 scales, 18 keys, 30+ chord types and 10 chord voicings. It can function as a VST or Audio Unit plugin, processing incoming MIDI events and/or generating outgoing MIDI. You don't need to use MIDI though: there is also a standalone executable which contains its own little synth for a fast start.