If dance music took root in the ‘90s, its branches grew every which way in the ‘00s. Techno and house went from underground concerns to worldwide forces, yielding timeless anthems like Daft Punk's “One More Time.” An increasingly global perspective blurred both genres and borders, giving us songs like M.I.A.'s “Paper Planes.” And the Y2K comedown produced a wave of enveloping (and occasionally melancholy) downtempo from Air, The Avalanches, Moby, Boards of Canada, and other artists keeping it easy like Sunday morning. Yet as dubstep kicked off toward the end of the decade, there was no shortage of earthshaking futurism.