Dolly Parton and Kelsea Ballerini are contributing to country music history! The stars performed together during Monday's 57th Academy Country Music Awards in Las Vegas' Allegiant Stadium.MORE: Inside ACM Awards host Dolly Parton's 56-year marriage to husband she met at 18For her performance with Dolly, Kelsea opted for a brighter look, closer to her country roots. She wore a short, baby blue romper with a banquette neckline, voluminous sleeves, and of course, brown cowboy boots.Dolly wasn't far from the country fashion, clad in a lace-up Western-style yellow top and a cowboy hat.WATCH: Kelly Clarkson to perform Dolly Parton tribute at 2022 Academy of Country Music Awards MORE: Exclusive: ACM Awards nominee Carly Pearce pays heartfelt tribute to 'inspirational' Dolly PartonFans went wild over the performance, fawning over how well the two star's voices melded together.