The newly engaged star shows off a diamond sparkler at the Met's Costume Institute Gala in N.Y.C. Plus: Mariah Carey, Ashton & Demi, Clive Owen and more

7 of 20

GUITAR HERO

She's a little bit country, a little bit rock 'n' roll! Carrie Underwood works the crowd Sunday while headlining the Stagecoach Country Music Festival in Indio, Calif. The singer performed her hit "Before He Cheats" – and even covered Guns N' Roses' "Paradise City."