- Any high school group is going to be greeted with some comparison to Glee.
- In Season 3, Sonos chose Boyz II Men's "It's So Hard to Say Goodbye to Yesterday" as their Swan Song upon elimination. Shawn was visibly embarrassed.
- In Season 3, Michael from the Dartmouth Aires shouted "Sing-Off!" in three of their performances. Four, if you count their audition video.
- The Yellowjackets' Swan Song (from Season 3) has several shout-outs, both to the judges and to the show.
- The Princeton Footnotes paused their performance to sing, "We love you Ben!" during season 4.
- Home Free and The Filharmonic's sing-off in season four was "I'm Alright", the signature song from Caddyshack, and their choreography featured nods to events in the film, including Home Free's Rob Lundquist doing the gopher's shimmy dance.
Shout Out / The Sing-Off