This Shirtless R&B Singer Is Hitting the Gym — Hard: Guess the Ab-tastic Star! (PHOTOS) 1 of 2 Prev Autoplay Next Tweet January 7, 2013 at 07:00PM EST by Laura Case Related: Wetpaint Entertainment, Hot Guys , Guess Who? full size Credit: Instagram Who's the Ripped Musician? Yeah, yeah, yeah, this guy is looking good!Still stumped? Click through for the reveal!