Kelly Clarkson is stretching again on "Stronger" (RCA). After consolidating all her pop prowess on her irresistible 2009 album, "All You Ever Wanted," she is trying her hand at a variety of genres -- from the acoustic country ache of "Breaking Your Own Heart" to the four-on-the-floor dance-floor stomper "What Doesn't Kill You." She handles it all very well, infusing her tales of empowerment after a breakup with her unique combo of vulnerability and sass. Clarkson is best at the pop put-down, though, and she has a doozy in "Einstein," where she declares, "I may not be Einstein, but I know dumb + dumb = you."
THE GRADE A-
BOTTOM LINE Masterfully covering all her bases