The 10-man acapella group, who found fame on Youtube after forming at Indiana University, continue to dazzle with their renditions of pop classic and modern chart hits with highlights "Let It Go", and Pharrell Williams' "Happy" catapulting the group to mainstream success. Catch them this summer on the Summer: The 90s Tour Part 2!

With an estimated 250 million in album and single sales, Rock and Roll Hall of Famer Rod Stewart arguably possesses one of rock's greatest and most distinctive voices. With that immediately recognizable husky voice, the gravel-toned wonder has successfully commanded nearly every genre of music including folk, rock, soul, R&B, blues and more.