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 StoreAudiobus is the app that makes the rest of your setup better.
iOS 7 Inter-App Audio - the technical details we've been waiting for
This is an Apple developers document, "Audio Unit Framework Reference" which is way over my head. But it has all the official details of audio unit hosting which is the foundation of inter-app audio.
Enjoy!
And thanks to Adil @rhism who gave a nice summary in another thread:
IAA introduces a new way for apps to send MIDI to each other ('new' meaning 'separate from CoreMIDI / Virtual MIDI'). An "AB input slot" app can be an IAA 'generator' node that just sends audio to its host, or it can be an 'instrument' node that receives MIDI from the host and sends audio based on that MIDI. So you can sequence the instrument node from the host.
https://developer.apple.com/library/ios/releasenotes/General/WhatsNewIniOS/Articles/iOS7.html (search for Inter-App Audio).
There are also 'effect' nodes that receive and send audio, and 'music effect' nodes that receive audio and MIDI, and send audio. Fun fact: the internal iOS code for an effect type node is 'aufx' :)
Comments
Now we only have to wait for Auria and Cubasis! .....and it shouldn't be too long of a wait now too.... :-)
Actually the internal code for an effect component is 'aurx', not 'aufx'
@j_liljedahl My mistake, I was reading from this page and saw this:
kAudioUnitType_Effect = 'aufx'
I guess that's for Audio Units not IAA. You'd think they'd want to eventually merge the two...
Right, but I guess there's a point in differing between ordinary built-in AU's (which can have multiple instances and runs in-process) and remote AU nodes (inter-app audio).
I'm pretty late to this but has anyone found any useful documentation for receiving MIDI from a host in an IAA instrument app? I can't seem to find anything.
@never_be_normal you might want to take your question to the Audiobus Developer Center.