This feisty singer's youthful charm and emotional openness helped her soar to victory on American Idol in 2007. In the years that followed, she's blossomed into a pop&B star, her powerful voice tackling midtempo laments like “Tattoo” as easily as it handles upbeat bangers like “S.O.S. (Let the Music Play)”. She's also put her Idol-honed versatility on display, pairing up with Chris Brown on the impassioned duet “No Air” and offering listeners inspiration on the determined “One Step At a Time”.