This is from the ACM awards show that is Carrie Underwood and Miranda Lambert singing and telling about their new songs. This just happened and the .brMiranda Lambert pops in as a surprise guest during Carrie Underwoods Party for a Cause performance. For more from the ACM Party For A Cause Festival .brCarrie Underwood, Miranda Lambert, Katy Perry, Dolly Parton, Brittany Kerr, Luke Bryan, Carolyn Boyer, Nicole Kidman, and Keith Urban make our best dressed .brThis is from the ACM awards show that is Carrie Underwood and Miranda Lambert singing and telling about their new songs. This just happened and the .