J.Lo in NYC Has Big Secret Party

8/24/2007 12:54 PM PDT

J.Lo in NYC, Has Big Secret Party

Jennifer Lopez is auditioning female dancers in NYC -- and last night she surprised them, bigtime, with a special performance by the diva herself.

J. Lo held a casting call at Roseland Ballroom yesterday, searching for a dancer for her new music video for "Do It Well." TMZ caught Mr. and Mrs. Marc Anthony pulling up to the venue last night, where Secret deodorant (!) threw a premiere party for Lopez's new album after the auditions. Lopez hit the stage for a high energy mini-concert inside, performing a medley of her songs for about 5 minutes for the amped up crowd.

Marc and Jennifer appeared to hundreds of fans and flash bulbs, shaking hands with people waiting outside, before taking off in their SUV. During the next month, Lopez is holding additional casting calls in five other cities; Dallas, Atlanta, Miami, Chicago and Las Vegas.