Ahh, this question. I enjoy all the songs too, but I like the classical music one the best. It's the one pretty much exactly based off of Rondo Alla Turca (heard HERE), a movement in Mozart's Piano Sonata No. 11. I've been a violinist for 10 years and counting, and I used to play the piano and flute as well, so I'm a huge classical music fan. I think it's a pretty well-known piece and it gets stuck in my head every so often.