I have a start to a game with the music I wanted. Upload your custom music to the backdrop, and select playsound ___________.
This is just the basis. You should know how to enter the project, go to the backdrop, and experiment with the My-Block attacks. Love and favorite if you want more. Follow me to stay updated on the projects I'm making. Thanks to @TheConstructer for the Lunar Whale attacks, the Pop Circles, and the player.