“Sekaiju” is free, open source MIDI sequencer / editor software for creating and editing MIDI data. You can record MIDI keyboard or synthesizer playing to the computer, and you can compose music to play with your MIDI modules or synthesizers. Since it allows editing of all kinds of events, and has an unlimited undo and redo feature, Sekaiju can also be used as a powerful MIDI editor. A real-time input which can input each MIDI channel messages into separate tracks at the same time is a popular feature .

openmidiproject.osdn.jp/Sekaiju