Use your keyboard to play notes C through A. You can even play chords!
See my new project, an improvement of this one: http://scratch.mit.edu/projects/26662747/ Credit to @Unrealization for creating the sprites, background, and some of the scripts. Credit to @TheLogFather for finding a way to stop a sound without stopping all the sounds. See his demo at http://scratch.mit.edu/projects/24414513/