VIDEO: 'Gossip Girl' Leighton Meester rocks out with Weezer! Encore or no more?

 

"Gossip Girl" Leighton Meester helped Weezer sing their new single, "(If You're Wondering If I Want You To) I Want You To." 

At an All Hallow's Eve performance in New York, aspiring pop princess Meester -- wearing colored tights, a black scuba top and a modified B-52 beehive -- joined lead singer Rivers Cuomo in a duet. 

He told MTV News how it all happened.

"We invited her down, and she was in rehearsal -- wait, did she even come to rehearsal? No, she didn't!" Cuomo said. He added, "We just worked on it in the dressing room right before the show. 'You sing this line, now I'll sing that line,' just like that. It's best when there's a little rehearsal, so that it can still feel spontaneous."

What do you think of Leighton's performance. Want more? We do!

Follow Dish Rag's gossip updates on Twitter!

Related "Gossip Girl" dish:

Leighton Meester's footsie sex tape allegedly on the web

Leighton Meester's new music video is hot

Ed Westwick and Chace Crawford dish 'Gossip'

Drew Barrymore snogging Ed Westwick?

Is Blake Lively a size zero? Really?

Blake Lively's brother made her do what?