Lady Gaga, Jennifer Lopez and a whole slew of other artists closed the iHeartRadio Music Festival with a bang Saturday night at Las Vegas' MGM Grand. Gaga's little monsters were out in full force, as were fans of Lopez and her fellow "American Idol" Steven Tyler and Randy Jackson, who both took the stage. Other performers of note: Nicole Scherzinger, Rascall Flatts, Kenny Chesney, Sublime, Natasha Bedingfield and Sting -- who even ...