Tim McGraw, Rascal Flatts and Carrie Underwood are among the artists who will perform at the Academy of Country Music (ACM) Awards on May 15 in Las Vegas. McGraw is nominated for entertainer of the year. Rascal Flatts' six nominations also include entertainer of the year. Underwood is up for five awards. Other performers now include Rodney Atkins, Miranda Lambert and Brad Paisley (male vocalist nomination). Previously announced performers include Brooks & Dunn, Kenny Chesney, Reba McEntire with Kelly Clarkson, George Strait and Sugarland. The show will air live on CBS.