mitch grass, avi kaplan and kevin olusola. >> wow. >> you know what's great about you guys, you weren'te singoff." how did you get together? >> the three of us grew up together, so we were going to try out for the show as a trio. but my friend was like, you should have a bass and a b-boxer. >> kevin we found on youtube. he was a cello beat boxing video. >> are you guys surprised at the fame, sold out concerts? >> yeah. >> it's been great. >> are you guys watching the show now? >> it's crazy. >> there's some good groups there. >> and is pitch perfect your favorite movie? >> anyway, you guys are going to sing angels we have heard on high, right? >> yeah. >> here they are. ♪ ah ah ah ah ♪ angels we have heard on high singing sweetly o 'er the plains in reply echoing their joyous name ♪ gloria gloria gloria in excelsis deo ♪ gloria gloria gloria in excelsis deo ♪ ♪ da da da da da da da da da da da da da da ♪ ♪ shepherds with your joyous strength ♪ ♪ gloria gloria gloria in excelsis deo ♪ gloria gloria gloria ♪ excelsis deo ♪ ♪ come adore on bended knee, christ the lord the newborn king ♪ ♪