Audiobus: Use your music apps together.
What is Audiobus? — Audiobus is an award-winning music app for iPhone and iPad which lets you use your other music apps together. Chain effects on your favourite synth, run the output of apps or Audio Units into an app like GarageBand or Loopy, or select a different audio interface output for each app. Route MIDI between apps — drive a synth from a MIDI sequencer, or add an arpeggiator to your MIDI keyboard — or sync with your external MIDI gear. And control your entire setup from a MIDI controller.Download on the App Store
Audiobus is the app that makes the rest of your setup better.
Is there any app that can transpose one midi signal by another?
[midi source A note value] + [midi source B note value ] = [output note value]
In practice, it’d probably have to do two further things:
- prioritise the note on/off values of one, the other, or combination of both, according to a setting (and sampling and holding the last note value of each input)
- if the two notes are adding, then they’ll end up higher than either, so it’d be nice to bring them back down
I can’t think of any app that allows this to occur. I don’t think it can be done in midi flow, or timid stuff, or midi designer, or, well, anything.