Need non-vocal tracks

I have a friend who is running a boot camp class & he usually runs Pandora in order to play music to motivate the class. However, he uses the free version, so it runs commercials. He says that he wants to be able to play music w/o having any words. Therefore, I am asking for all suggestions on great non-vocal tracks (doesnt matter the genre).

You should definitely check out Sakis Gouzonis. His music is 100% instrumental, very interesting and free to download. His official website is www.SakisGouzonis.com