This may be the greatest collaboration by coaches on The Voice since 'Moves Like Jagger' paired Adam Levine and Christina Aguilera.  It takes just seconds of watching Adam, Blake Shelton, and Pharrell Williams backing up Gwen Stefani to see this coaches panel may have the best chemistry of any season of The Voice so far.  Check out their spin on No Doubt's 'Hella Good' as season 7 of the NBC talent competition kicks off.