By Nathan Poppe Entertainment Writer npoppe@oklahoman.comTwo minutes before joining the Rolling Stones onstage, and Grace Potter's clothes are falling off. Not an ideal way to sing “Gimme Shelter” for 50,000 screaming fans alongside a preening Mick Jagger. “The entire back of my dress, where my sister had sewn on my microphone pack, busted open,” Potter, 31, recalled in a recent phone interview to promote her performance at this weekend's OKCFest. Queue the Stones’ watchful wardrobe team, which includes Keith Richards' daughter Theodora.Read more on NewsOK.com