Sir Mix-A-Lot performed his classic song "Baby Got Back" at Benaroya Hall in his hometown of Seattle. While Sir Mix-A-Lot has probably performed a lot in Seattle over the years, he has never been backed by an orchestra. Until now. Contemporary composer Gabriel Prokofiev assisted in the one-of-a-kind performance. Joining Sir Mix-A-Lot and the orchestra on stage was a group of mostly middle-aged white women, who really brought out their dance moves.