Apple makes a Camera Connection kit for their iOS devices, such as iPad and iPhone. You will need one of these so that you can plug a MIDI controller into your device via USB. Most MIDI controllers will have a USB output.
Turn the MIDI controller off, then connect a USB cable from its USB output to the Camera Connection Kit Adapter’s USB input. Once connected, power on your MIDI controller.
If you get a power consumption warning on iPad, make sure you power your MIDI controller using its power supply or a powered USB hub.
There’s no visual feedback that you’ve connected the controller properly, so you’ll just have to try it with an app to verify you’ve got everything connected properly.
Open the Animoog or other Moog Music app and try to play some keys on the controller. If you’re getting sound when you strike a key, congrats, you’re ready to play music. If not, follow the next step.
Once connected, open your app and go to SETTINGS > MIDI. You’ll want to confirm that both your MIDI controller and your app are both communicating on the same MIDI channel. By default, your app and most likely your MIDI controller will default to CH 1.
Exit SETTINGS and try playing a few notes on your controller. You should be hearing your app respond accordingly.
TIP: you’ll need a class compliant MIDI controller (doesn’t require software to run) and may need to power your controller with a power supply if it’s not bus powered.