Few bands can pull off entire cover sets without prior rehearsals. But that’s exactly what Varmint has done, a precious few times a year since 2005. Anchored by Seattle roots-jazz staples Robin Holcomb (vocals), Wayne Horvitz (organ), Jon Hyde (pedal steel), Tim Young (guitar), Andy Roth (drums), and Keith Lowe (bass), Varmint has worked out an impressive set of liquidy avant-twang, covering tunes as far-flung as Al Green’s soulful take on Hank Williams’ “I’m So Lonesome I Could Cry,” Sun Ra’s “Enlightenment,” and Michael Hurley’s “Mister Man on the Moon.” This year’s annual holiday show will feature a normal set of such covers, plus an additional set of early Grateful Dead tunes, dubbed “The Golden Road” (in reference to the opening number on the Dead’s 1967 debut). Listening to the material Varmint has covered in the past, such as Holcomb’s rendering of the traditional “Black Jack Davey” or the stoned honky-tonk of “Portland Water,” it’s obvious that early Dead is a natural outgrowth of the musical trip Varmint was already on. You can detect the influence Jerry Garcia had over guitarist Young, and the restrained hillbilly-blues-jazz shuffle of drummer Roth reeks of Bill Kreutzmann. And the fact that they haven’t rehearsed brings them that much closer to honoring the Dead’s true legacy. BRIAN J. BARR

Sat., Dec. 27, 8 p.m., 2008