The roster of performers for the Sixth Annual Jammys continues to expand. The latest additions are Mickey Hart, Billy Kreutzmann, Stephen Marley, Ky-Mani Marley and Charlie Musselwhite. While details on the collaborations will remain undercover until the night of the show, it is fair to say that the Rhythm Devils, Hart and Kreutzmann, will team up in one musical segment (with additional musicians participating as well). In addition, Stephen and Ky-Mani Marley will take the stage together as part of a separate segment. The Jammys will return to The Theater at Madison Square Garden on April 20, with tickets currently on-sale.