Well folks, I’m continuing to try and help you out for questions in the comments. Let’s see if this Synth One specific video helps. I suspect that the issue with the MPC not seeing audio is due to the user not hooking up the audio outputs from their iPad/iPhone to the MPC, but just a guess. Hopefully this will help.
For those who don’t know, Midi only carries note data such as what note number and velocity, it does not carry audio information.