USA Today - USA - A whole lot of uptown girls grooved to Billy Joel Saturday night.

Renee Zellweger, Kelly Ripa and Mary-Kate Olsen danced as Joel performed at the Social @ Ross concert, a series of events that is becoming the marquee bash of the already glitzy Hamptons party circuit. The musical extravaganzas previously featured Prince and the Dave Matthews Band, and with tickets selling for $4,000 each, it's no wonder the night is a lavish one.

Zellweger clapped her hands and danced with a mystery man to Joel's encore of Piano Man. Ripa grooved along with her husband, Mark Consuelos. Alec Baldwin stood in the