Ignore bad reviews Music Io is great – musicIO: Audio and MIDI over USB Review
I have been using this app with ableton since its release for audio / midi . It works better than my I connect midi 4+ which was $300. Most of the negative reviews I am reading here are from people who either sound like they didn't understand what this app does or are trying wonky nonstandard configs. If you are using ableton and know what you are doing you will not be disappointed.
Review by Anton Brecht on
musicIO: Audio and MIDI over USB.