Faith Hill, Toby Keith, Martina McBride and Big & Rich are the final performers announced for the 42nd annual Academy of Country Music Awards show taking place Tuesday (May 15) in Las Vegas. Big & Rich will be joined by R&B vocalist John Legend, who is featured on "Eternity," a track from the duo's upcoming album, Between Raising Hell and Amazing Grace. The ACM also announced Thursday (May 10) that Shania Twain will also participate in the show, marking her first awards show appearance in two years. Just announced as presenters are Sara Evans, Heartland, Craig Morgan, Joe Nichols, Kellie Pickler, Chris Young, Brad Mates (Emerson Drive) and Darius Rucker (Hootie & the Blowfish). Other newly-announced presenters include CSI: Crime Scene Investigation stars Gary Dourdan and Eric Szmanda, Dr. Phil and Robin McGraw, former professional volleyball player and model Gabrielle Reece, actress Emma Roberts and actor Luke Wilson. CBS will telecast the awards show live from the MGM Grand.