December People’s blend of anthemic hard rock, Christmas songs and charitable spirit makes one final tour.

From a marriage of “Silent Night” and Pink Floyd’s “Us and Them” to a blending of “Joy to The World” and The Who’s “Won’t Get Fooled Again” to a mashup of “Jingle Bells” and Van Halen’s “Hot for Teacher,” half the fun of a December People show is figuring out which classic rock tunes they reconfigure with the lyrics of holiday favorites.

December People’s Golden State Theatre show is billed as their Farewell Tour. “[Robert Berry] said, ‘It’s been a good run for us, but we may not do it again,’” guitarist Gary Pihl reports.

Along with Berry (Greg Kihn Band) and Pihl (Boston), DP features drummer David Lauser (Sammy Hagar Band), keyboardist Dave Medd (The Tubes) and guitarist Jack Foster.

Since DP is made up of professional musicians who are all simultaneously involved with other touring bands, it has always been problematic getting everyone together at the same time. DP has had to deal with their share of sudden personnel changes throughout the years. Pihl had to skip DP’s 2016 and 2017 runs when Boston reunited for some heavy touring.

Though Pihl can’t go into too much detail, he says Boston is in the midst of something that will take up a lot of his time in the near future.

“We try to fill in where we can, but it wouldn’t be [December People] if we had to get five replacements,” Pihl says. “We’re just glad we have been able to do it for as long as we have.”

Since the group was born out of the holiday spirit, DP partners with a local charity in each community they perform. Since 2010, the band has regularly appeared in Monterey County.

“[The charity partnerships] are always been immediate gratification for us and something we’ve been thrilled to be a part of,” Pihl says. (Thursday’s show is a benefit for Monterey County’s chapter of Guitars Not Guns.)

Something else that makes the DP concert experience unique: Following every show, the bandmembers head directly out to the lobby for a casual meet-and-greet with fans. And they sign albums of any of the bands they are associated with.

December People was born shortly after a record label approached Berry to put together a holiday record. One holiday record expanded into the birth of December People, five albums and a string of shows every holiday season for nearly a decade.

Expect a few new DP mashups during this year’s show.

DECEMBER PEOPLE 8pm Thursday, Nov. 15. Golden State Theatre, 417 Alvarado St., Monterey. $32-$50. 649-1070, goldenstatetheatre.com