Android game clone Piano Master or similar

I need to make a "falling piano notes" game, like "Piano Master". Resolution will be 640x360 pixels. Format of music script should be MIDI properly adapted, so you are free to suggest me which MIDI editor is best to adapt a standard MIDI file. Development should be through Basic4Android (B4A) Android development system. Game will be split into B4A classes, code modules and/or libraries as much as possible. I don't need the complete game, I just need a working prototype, because the final touches will be carried on by me. A subsequent project will join this project to manage a bluetooth midi piano keyboard. If you can manage this part, please, let me know. Bidders are required to attach an "hello world" B4A project, otherwise bids will not be considered.