Assuming you are using a version of MMM with this feature (you didn't say), one would use the Vita MIDI editor to create their own loops. You have a wide variety of instruments to choose from. In MM-15 you will find it under the Synthesizer tab.
Assuming you are using a version of MMM with this feature (you didn't say), one would use the Vita MIDI editor to create their own loops. You have a wide variety of instruments to choose from. In MM-15 you will find it under the Synthesizer tab.