Where is it? Find the tutorial at: https://docs.repl.it/tutorials/12-audio
What is it? Find, download, play, and control the volume of your music, all in code. If that's not enough, create your own music too.
What do you need to follow? A bit of Python experience is ideal, but you should be able to keep up even without it. You'll do everything from your browser so no Python set up is required. You can create a free account on Repl.it to save and share your code.