RIPPLE EFFECT

"Empire State of Mind" by Jay-Z and Alicia Keys falls from its perch (No. 1 to No. 2) after a five-week run. In a rare chart occurrence, an acoustic version of "Empire" by Keys debuts at No. 55. Most often, different takes of a song are merged with the original versions for the purpose of chart rankings, but in the instance where a contributing vocalist (Keys) takes the reigns without help from the lead act (Jay-Z), the songs are tracked separately.

Rihanna's new single "Hard," featuring Jeezy, hops 21-11. Lady Gaga's "Bad Romance" holds at No. 3, while Jay Sean's "Down" rebounds 10-8.

The Black Eyed Peas slip 8-9 with "Meet Me Halfway," while Eminem has the chart's Hot Shot Debut, coming in at No. 29 with "Hell Breaks Loose." The track appears on Eminem's re-released "Relapse: Refill."