Mary-Kate and Ashley Olsen began their celebration on June 12, by exploring downtown Nashville's Lower Broadway, where they stopped into The Wheel, a honky tonk bar, listened to the Rob Skaggs Band and drank diet Red Bull and Patron. "They were just having a good time with their friends," says an observer. "Everyone was laughing and dancing. They all seemed very relaxed."
On Friday, June 13, the two hosted a private dinner party in the State Room at the five-star Hermitage Hotel with eleven of their friends, and Josh Groban, who made a surprise visit. The former Full House stars left the hotel around midnight and then rocked to a My Morning Jacket concert till 3 a.m.
On Saturday, June 14, the girls were spotted with their pals at the Pearl Jam concert, at the Bonnaroo Music Festival, dancing on the VIP balcony for three hours. Mary-Kate, dressed in jeans and a baggy flannel shirt, and Ashley, wearing a black hat and white shirt, jammed as the Seattle rock band played "Evenflow" and "Alive." They never stopped dancing.
The twins capped off the weekend celebration on Sunday, June 14, when they left the Hermitage Hotel, wearing sunglasses, carrying armloads of bags, and, yes, one cup of Venti Starbucks.
Reporting by SHELLEY AKERS, WENDY GROSSMAN and KAY WEST