OK Go: The One Moment. (YouTube, 4:12min)
There are two videos that show what went on behind the scene (and before the scene, so-to-speak):
OK Go Sandbox: One Moment of Math (YouTube, 4:33min) and The One Moment” BTS (YouTube, 5:03min).
Bonus link to the first OK Go video I ever saw: This Too Shall Pass – Rube Goldberg Machine.