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.
DerVoco in Beatmaker 3
I added DerVoco as an AU MIDI FX app to a sound bank in Beatmaker 3 and routed MIDI from Fugue Machine to the bank and it worked as expected. I added DerVoco as an AU FX app to a sound bank in Beatmaker 3 and routed MIDI from Fugue Machine to the bank and had no sound until I used the keyboard in the DerVoco AU which what I would have expected. The Beatmaker 3 keyboard will respond to the MIDI in either instance but only the MIDI FX instance will output sound. Below is the DerVoco AU FX screenshot.