Sandbox and playing Midi
The fix is to add a couple of entitlements:
- com.apple.security.device.microphone
This one allows your application to access the microphone. - com.apple.security.temporary-exception.mach-lookup.global-name
This allows talking to the MIDI Server which coordinates all the Midi functionality across applications. - com.apple.security.temporary-exception.audio-unit-host
This allows talking to audio components which are not itself sandboxed.
For more details, please check developer.apple.com/library/mac/qa/qa1483/.