Be your own composer with this stunning idea: 16 different YouTube videos on a single page, all with musicians/artists playing in the same key and being generally ambient. The result: the youtubes are your own personal samplers, and as you start and stop each segment, you create and conduct your own song.
I like 5-8-16 with 8 at 2/3rds volume. 8 is spacy and cool but it's a little too loud. 12 is a lovely background, and then you can add more of a lead instrument like the trumpet. But hell, almost any combination works!
Before you go, make sure you have A) 15 minutes to kill, B) your sound up. NSFW, only because it'll make 15 minutes of music and then they will know you're just fucking around on the internets.
http://www.inbflat.net/