Bang your head to the songs of Spinal Tap and strum your banjo to the tunes of the Folksmen at UNWIGGED & UNPLUGGED: AN EVENING WITH CHRISTOPHER GUEST, MICHAEL MCKEAN, AND HARRY SHEARER. The creators/stars of This Is Spinal Tap and A Mighty Wind offer an unplugged concert of their amusing music, and it should be hilarious to hear acoustic arrangements of "Big Bottom" and other hits from one of the world's loudest bands. But if they're unplugged, how can they turn it up to 11? $35.50-$52.50. 8 p.m. Fox Theatre, 660 Peachtree St. 404-881-2100. www.foxtheatre.org.