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.
os 16 failed
I just tried to update to os 16 (on a 6th gen 2018 ipad, with 4.5 gb of space free), and got an error message saying "update failed" - no further elaboration.
Part way through the process, the ipad asked me if I wanted to offload some apps in order to free up space (on a temporary basis - sounded like they would be immediately reinstated after update was complete). I replied "mais oui"