"Regional Holiday Music" is the third and final Christmas episode of Community that aired on NBC on December 8, 2011.
While meeting in the cafeteria, the study group reveal their plans for Christmas. Some are spending time away, disappointing Abed (Danny Pudi), who had wished to spend the holidays with the group, even renting the critically reviled Inspector Spacetime holiday special to watch with them. Their conversation is interrupted by a performance by the obnoxious Greendale glee club. Midway through, Chang (Ken Jeong) stops them with a cease and desist order from ASCAP—tipped off by Jeff (Joel McHale)—for performing copyrighted music without permission. The glee club members suffer a nervous breakdown and are taken to the hospital.
The glee club instructor, Mr. Rad (Taran Killam), invites the study group to join and perform the Christmas pageant but is rebuffed promptly due to their collective dislike for the club. However, through a series of events performed as songs, the members of the group are lured into joining the club one by one.
- "Glee": Mr. Rad manages to convince Abed to join the club by tapping into Abed's desire to spend Christmas with the group.
- "Christmas Infiltration": Troy (Donald Glover) is next to join when Abed reaches out to his desire to celebrate Christmas with the group despite being a Jehovah's Witness. Troy then raps about going undercover to make it seem like he accepts Christmas.
- "Baby Boomer Santa": Troy & Abed exploit Pierce's (Chevy Chase) baby boomer narcissism using mixed musical styles associated with each of the decades Pierce has lived through.
- "Teach Me How to Understand Christmas": Before this song, Annie (Alison Brie) catches the glee club virus after being cornered by Troy, Abed, and Mr. Rad. She then dresses up in a sexy Santa outfit to seduce Jeff.
- "Happy Birthday Jesus": Pierce invites a children's choir to sing to Shirley about how the public school system has thrown out the meaning of Christmas (the birth of Jesus) during its celebrations. Unable to resist her religious fervor, Shirley springs into song, proclaiming "Happy Birthday Jesus!"
With Britta (Gillian Jacobs) the only non-glee club member left, she seeks out Jeff, only to find that he too has been turned.
As the group is backstage preparing for the Christmas pageant, Mr. Rad informs Abed of his long-term intentions for the group. As Abed had only made the group join to brighten up Christmas, he sets forth upsetting Mr. Rad's plans. While the group performs "Planet Christmas" on stage, he asks Britta (who was originally cast as the mute tree) to replace him as the Mouse King. She does and ruins the pageant with her poor singing and bad, improvised lyrics and choreography.. Despite Mr. Rad's objections, Dean Pelton (Jim Rash) and the audience supportively agree to "let Britta finish her awkward song" in the spirit of inclusion. However Mr. Rad then becomes enraged at the idea and inadvertently reveals that he caused the bus crash that killed the glee club members mentioned in "Paradigms of Human Memory" before distracting everyone and running off. Abed regretfully concedes that "forcing things to be bright just makes the darkness underneath it even darker."
Back at the apartment, Abed is watching Inspector Spacetime alone. The group suddenly arrives and they announce that after a dark year, they have cancelled their plans in order to spend the holidays with him. The episode ends with them joining him in viewing the Inspector Spacetime holiday special.