This post outlines the current MIDI compatibility, and shows how the new prototype being played for the first time.
Unfortunately, lots of stuff has gone wrong these past few days and I have had to redo a lot of the electronics. One of the MPR121 boards has blown, a couple of the piezo leads snapped off, even the speaker has blown! Basically, not what you want on the day of the deadline, but hey, we're getting there 
The Bela platform currently supports MIDI in over USB. Something I kind of assumed is that I would be able to get MIDI out from my iPad and set up a custom control page on Lemur to control some parameters on the Kazumi patch. Unfortunately, as this isn't the case, I have only been able to test this using an AKAI LPK25 keyboard, as it's the only MIDI controller I have around. I hope that sometime soon they add support for receiving OSC over WIFI or Bluetooth as this will be ideal.
Here's a short clip showing how I can use the keyboard to set which key the scale is set to. This is something that I wanted to implement with one of the rotary encoders but, unfortunately, I haven't had time to implement digital I/O on Bela. They are currently working on supporting this natively within the Pure Data compiler but for now, any digital I/O has to be implemented in the custom render.cpp file.