Mick Jagger's New Group SuperHeavy Unveils Music | Billboard.com: Details about the Mick Jagger-Dave Stewart supergroup SuperHeavy have been released slowly and the first public introduction of the music was almost as cagey. Jagger, Stewart, soul singer Joss Stone, reggae artist Damian Marley and film composer A.R. Rahman gathered to speak about the making of the album after about half of it was played -- no song titles provided -- Thursday (June 30) afternoon at the Jim Henson Studios in Los Angeles. Their chat emphasized the unique nature of the project and the random way in which the music, a multi-cultural free-for-all at the start, came together.