"It's a bit mad sometimes, you go from one sound to the other," Joss Stone says with a grin about the new album from SuperHeavy, the star-studded group she played in alongside Mick Jagger, Dave Stewart, A.R. Rahman and Damian Marley. Stone chatted with Rolling Stone about Jagger and Marley's painting-as-songwriting style, the challenge of adding something to a Jagger or Marley-penned tune and her hopes that one day SuperHeavy will find time in their busy schedules to play live.