What's That Sound? The Rhythm That Ruled 2011

There's one sound that pretty much dominated pop music this year. Monster hits by LMFAO, Adele, Katy Perry, Nicki Minaj, Britney Spears and more all relied on the hammering beat known as "four-on-the-floor."

"You feel it in your whole body, just on every beat: boom, boom, boom, boom," says Jordan Roseman. "It's so easy to understand, it's almost hard not to move to it."

Roseman, better known as DJ Earworm, is intimately familiar with these songs and their matching beats. He mixed them all together in his annual mashup of the year's biggest pop hits, a series he calls "The United State of Pop." He says that four-on-the-floor, while not a new sensation, dominated the radio dial in 2011.

"It goes back to disco. Right when these big speakers came along, all of a sudden the kick drum took this new prominence in music because you could really feel it," Roseman says. "It's definitely peaking right now."

You can download Roseman's 2011 mashup, "World Go Boom," at the DJ Earworm website.