Z100's Jingle Ball 2011

Tis the season for Z100's annual pop takeover of MSG! This chart-topping spectacle includes sets by Kelly Clarkson, David Guetta, LMFAO, Foster the People, Hot Chelle Rae and, get ready…the one and only Lady Gaga. The megahitting awesomeness of this bill can't be denied, but good luck getting in—the kids grabbed all the tickets eons ago.