There are two ways of looking at Tuesday night's headlining act at the 9:30 club: Half the Doors showed up -- or half the Doors didn't.

This audience took the optimistic outlook, roaring as original Doors Ray Manzarek and Robbie Krieger led an enhanced tribute band through 90 minutes of prototype downer rock.

Keyboardist Manzarek and guitarist Krieger, joined by former Cult vocalist Ian Astbury, are touring as the Doors of the 21st Century, or D21C. That moniker was the result of litigation from the estate of original frontman Jim Morrison, who died in 1971, and drummer John Densmore, who wanted no part of a reunion and was against the use of his old band's name and logo. (A judge even ruled that Morrison's estate and Densmore are entitled to share D21C's profits, despite their lack of participation and support.) Manzarek, who looks fabulous for a 66-year-old rocker, slandered Densmore again and again from the stage, and urged fans to surf to a Doors Web site to e-mail character and sexual slurs to his former mate.

The Doors were one of the 1960s' spaciest major pop acts. But over time spacy ferments into doofy. Astbury, who does a spot-on impersonation of actor Val Kilmer (the movie Morrison), appeared to be channeling the late frontman while breaking into very Doorsy rambling non sequitur binges. During "Wild Child," Manzarek, who has been spewing nonsensical verbiage into microphones since Astbury was in diapers, countered with "We're drowning with a hamburger!"

Yet Krieger's playing, which harks back to both B.B. King and John Philip Sousa, has lost none of its appeal or power over the decades. He broke into "Eleanor Rigby" during an already gorgeous solo on the biggest Doors hit, "Light My Fire." And even non-Doors fanatics would have to admit that Manzarek's organ playing conjured a rock-and-roll heyday. Best of all, nobody onstage ever uttered the phrase "We'd like to play something new for you."

-- Dave McKenna