The Google Play Music app that came pre-installed on my Android phone can play MIDI files, meaning that it has a library of MIDI voices it can access and use.
Are these voices part of the app specifically, or part of the Android OS code? If I am creating an app that creates MIDI data, is there a way I can access these voices in order to create and play notes from within the same app?
Android includes the SONiVOX Embedded Audio Synthesizer, which is not directly accessible from apps, except through the JetPlayer class.
However, the synth is open source, so it would be possible to compile the native library into your app.