Oh, I understand better now, though I don’t think I can be of much help. I have not done anything with Android, so there may be someone else who is better suited to help.
But, if I were in your position, I would probably not start with the code you linked to above & rather work through the tutorials related to Audio (if you have not already) and then move onto other ideas.
http://docs.juce.com/master/tutorial_audio_device_manager.html
http://docs.juce.com/master/tutorial_playing_sound_files.html
http://docs.juce.com/master/tutorial_looping_audio_sample_buffer.html
Good luck!