Just click each button for the music to play. To stop each song, press the stop button. PLEASE remember to stop a song before you start another one, as this will mess up the program if you try to play two songs at once. If you spot any bugs please report them as it is hard to debug three whole 40 megabyte files. :-)
I downloaded each song from the Portal Wiki page for the Soundtrack. They can also be downloaded here: http://www.thinkwithportals.com/music.php Disc 1 MusicBoard link: https://scratch.mit.edu/projects/111321145/ Disc 3 MusicBoard link: https://scratch.mit.edu/projects/111325494/
