Stars Come Out for New York's Fashion Rocks Concert

New York's famed Fashion Week has kicked off with a bang, as celebrities from coast to coast turn out to watch the year's hottest collections.

Last night's Fashion Rocks concert at Radio City Music Hall saw everyone from 50 Cent, Maroon 5, Avril Lavigne and Jennifer Lopez rock out to a crowd of fashion insiders.

“Entourage” star Jeremy Piven played host to the crowd, which included the top insiders from fashion and music.

Presenters included Max Azria, Mischa Barton, Sean "Diddy" Combs, Teri Hatcher, Tommy Hilfiger, Michael Kors, Sean Lennon, and LeAnn Rimes.

J Lo dazzled the crowd when she began her powerhouse performance wearing a sequined trench coat, which she tore off to reveal an itty-bitty baby doll dress. She wore knee-high boots the whole time.

One of the night's biggest surprises was when Aerosmith's Steven Tyler began belting out “Walk This Way” as Fergie joined him on stage.

On the red carpet, black was the color of choice for Hollywood's elite. Everyone from Jessica Alba to Tyra Banks wore the color. Even Nicole Richie showed off her growing baby bump in a black and white halter gown.