Country Music Association artists gathered in Nashville earlier this summer to perform at a four-day festival, and tonight ABC presents a three-hour compendium of that event, with heavy emphasis on the many musical performances. Carrie Underwood and Brad Paisley (pictured)  take the stage together, and other artists stepping up to the microphone include Miranda Lambert, Taylor Swift, Charlie Daniels, Keith Urban, Lenny Kravitz and others. Little Big Town hosts.