This is a little trippy. The band Flaming Lips once released a studio album containing four CDs designed to be played all at the same time. Flaming Lips has upped the ante and uploaded 12 different clips to YouTube, which are all supposed to be played on 12 different smartphones at the same time (or browser windows, if you don't have 12 iPhones). Here's their YouTube account with all of the videos on it, and here's an "instructional" video (beware: the title of the song is not safe for work) detailing how to get the tracks running and synced up on an iPhone.
Like I said, trippy. If you're not a Flaming Lips fan, the whole thing is probably too weird to put in the effort, not to mention that you probably don't have 12 smartphones sitting around to play music with unless you're in a particularly high-tech and relaxed office space. But it's a cool angle on music composition, and it's a neat experiment made possible with YouTube and our favorite smartphone. If you do have the time and energy to make it work, let us know what you think.