Pentatonix is an a capella music group, consisting of Scott Hoying, Kirstie Maldonado, Mitch Grassi, Avi Kaplan and Kevin Olusola. The group rose to fame following their victory in the third season of NBC's The Sing-Off. The group appeared in Sesame Street's 44th season, performing a "Number Medley." (First: Episode 4421) The group appeared in The Muppets episode "Pig's in a Blackout" performing their song "Can't Sleep Love" during an electricity-free episode of Up Late with Miss Piggy.