Fans of This Is Spinal Tap will understand why today is Nigel Tufnel Day: 11/11/11 honors the lame-brained rocker who had his amp’s knobs specially made to go to 11, ostensibly giving him more sonic power than the ordinary scrubs whose volume maxed out at 10. The joke still works, even if today’s music fans don’t listen to devices with old-school knobs. Indeed, 27 years after its release, Rob Reiner’s classic mockumentary has managed to avoid the fate of the fictitious band it chronicles. Rather than trundling along on nostalgia, Spinal Tap makes its influence felt with every episode of The Office. And, in a season marked by big, pretentious documentaries about the likes of Pearl Jam and U2, a movie that lampoons music-industry self-regard still seems crucial. Sure, rock may be dead, but Spinal Tap still goes to 11.

The film shows at 11 p.m. at AFI Silver Theatre, 8633 Colesville Rd., Silver Spring. $11. (301) 495-6720.