Claire de Lune, by Claude Debussy, with graphical score.
Q: What movie did I hear this song in?
A: You most likely heard it in Ocean's Eleven. It was also in Ocean's Thirteen, Twilight, Casino Royale, Gran Turismo 4, Seven Years in Tibet, Atonement, Man On Fire, The Darjeeling Limited, Ficció, El próximo oriente, The First Day of My Life, The Right Stuff, Antonieta, and The Game
Q: How did you make this?
A: With a program I wrote in Python. I also used FFMPEG, SoX, TiMidity, FluidSynth, Python Image Library, and midicsv. All excellent, free, open-source software.