Justin Timberlake's iHeartRadio Music Festival Performance Includes Premiere Of New Music

LAS VEGAS — There's a reason why Bruno Mars is set to perform at the Super Bowl halftime show. The pop crooner was in perfect form at the iHeartRadio music festival Saturday night at the MGM Grand Garden Arena. He wowed with his slick moves and energetic vibe. Justin Timberlake was also a fan favorite. The pop star closed the five-hour plus concert, singing hits like "Mirror" and "SexyBack." Paul McCartney kicked off the show, playing a bunch of new songs from his upcoming album. And R&B singe...