There is NO mistaking that guitar riff. You hear it and immediately know Guns & Roses "Sweet Child O'Mine is about to rock your face off! Carrie Underwood was performing at the Stagecoach festival in California when her guitarist hit the riff! The crowd went nuts and Carrie started to sing the song. And then welcomed the audience to the "greatest night of my life" and introduced Guns & Roses frontman Axl Rose! He joined her on stage to sing not just one but TWO songs. They followed up with "Paradise City". Carrie called Axl one of her heroes that taught her to sing. She'd already performed with Steven Tyler from Aerosmith so why not?! Carrie is totally a closet rocker and WE LOVE IT! Check out the performance below.