The Academy of Country Music honors country music's flashiest and sassiest at 8 Sunday night on CBS, and only ET is with nominee KELLIE PICKLER at rehearsals in Las Vegas!

Kellie has taken the country music world by storm with her Small Town Girl album, and now she's up for Top New Female Vocalist against TAYLOR SWIFT and SARAH BUXTON. Kellie will be performing her new single "Don't You Know You're Beautiful" on Sunday. LeAnn is up for Top Female Vocalist against CARRIE UNDERWOOD, MIRANDA LAMBERT, MARTINA McBRIDE and Taylor Swift, and Montgomery Gentry is up for Top Vocal Duo against BIG 'N RICH, BROOKS & DUNN, HALFWAY TO HAZARD and SUGARLAND.

There's still time to vote for Entertainer of the Year. Cast your virtual ballot for nominees KENNY CHESNEY, BRAD PAISLEY, GEORGE STRAIT, KEITH URBAN or RASCAL FLATTS by going to www.voteacm.com.