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.
Black Fugue / Pink Floyd Shoutout
Sorry for the clickbait but you will hear The Wall in this one. Originally White Fugue... but turned black overnight. Entirely Fugue Machine and the best one so far, I believe. SynthMaster1 provided the awesome bass patch in the beginning. Cubasis acoustic piano holds its own and cuts thru a mix quite nicely. 16 tracks in all.