Singer Josh Groban guest stars as himself, John Lloyd Young appears as wood shop teacher Henri St. Pierre, and Victor Garber and Debra Monk play Will's parents.

The episode features covers of seven songs, including the instrumental piece "La Camisa Negra" performed on guitar by Mark Salling.

Studio recordings of two of the songs performed were released as singles, available for digital download, and two of the tracks also appear on the album Glee: The Music, Volume 1.

"[1] When Rachel Berry (Lea Michele) questions director Will Schuester's choreography skills during a glee club rehearsal, he forms an all-male a cappella group, the Acafellas, to build his confidence.

The group originally consists of Will, football coach Ken Tanaka (Patrick Gallagher), woodshop teacher Henri St. Pierre (John Lloyd Young) and Howard Bamboo (Kent Avenido), a co-worker of Will's wife Terri (Jessalyn Gilsig).

Recurring cast members who appear in "Acafellas" are Stephen Tobolowsky as former glee club director Sandy Ryerson, Patrick Gallagher as football coach Ken Tanaka, Iqbal Theba as Principal Figgins, Kent Avenido as Sheets and Things employee Howard Bamboo, and Naya Rivera and Heather Morris as glee club members Santana Lopez and Brittany Pierce.

"[9] The episode features cover versions of "For He's a Jolly Good Fellow", "This Is How We Do It" by Montell Jordan, "Poison" by Bell Biv DeVoe,[10] "Mercy" by Duffy,[11] "Bust Your Windows" by Jazmine Sullivan,[12] "I Wanna Sex You Up" by Color Me Badd and an instrumental performance of "La Camisa Negra" by Juanes.

"Bust Your Windows" is also featured on the soundtrack album Glee: The Music, Volume 1, with a studio recording of "I Wanna Sex You Up" included as a bonus track on discs purchased from Target.

[18] Raymund Flandez of The Wall Street Journal praised Riley's rendition of "Bust Your Windows" as "showstopping", Vocal Adrenaline's "Mercy" as "leg-splits-over-shoulders exciting", and deemed the Acafellas performance of "I Wanna Sex You Up" "corny" but noted: "this is about high school.

"[19] Shawna Malcom for the Los Angeles Times wrote that although "Bust Your Windows" was "over the top [...] the emotion behind the whole thing felt appropriately real.

"[21] He commented that while "Acafellas" did not match the standard of the pilot episode, it was funnier than "Showmance", and praised the return of Stephen Tobolowsky as Sandy Ryerson.

[21] Hale called Groban's cameo the "most fun of all" in the episode, but overall noted that: "The humor can’t make up for the lack of big production numbers [...] The problem for this show is always going to be how to fill the gaps between songs.

"[1] Ray wrote, Glee's "upbeat message" was "overridden by the show's attempt to be darker than the run-of-the mill high school drama.