By now, we expect Demi Lovato [1] to wear a supersexy dress on the red carpet [2], but the singer surprised us this week by choosing a demure LBD to attend the Samsung Hope For Children Gala in New York City. In a black frock with ribbon details and black booties, Demi's toned arms and legs were the center of attention, but once it came time to perform her new song "Cool For the Summer," Demi replaced her classic dress for a racy look that showed off her abs. See the sparkly top and short shorts Demi wore on stage, then learn the real meaning behind "Cool For the Summer" [3] and watch a video of the funniest interview Demi has ever done. [4]