BY EVAN HAGA

It's difficult for old punk bands to stay broken up-there's money to be made on the club circuit and no serious contenders to take their place. That's certainly true of X, the Los Angeles-based quartet whose initial run in the 1970s and '80s produced some of punk rock's sharpest, most poetic documents. Since that time, punk has experienced dozens of permutations, alternately abstract, militant and precious, but rarely better. As the band's June 6 performance at Baltimore's Rams Head Live! affirmed, punk was best left to intelligent, bohemian young adults.

X has made that point again and again on sporadic tours throughout the last decade, and at the Coachella and ATP festivals earlier this year. Despite reports of recent songwriting, this original lineup-vocalist Exene Cervenka, vocalist/bassist John Doe, guitarist Billy Zoom and drummer D.J. Bonebrake-hasn't released an album of new material since 1985, and that's not necessarily a bad thing. Similar reunions-say, the live furor of the Stooges-came with a caveat in the form of a dull new album. It's far easier for artists to act like their younger selves than think like them.

For this current U.S. tour, dubbed "Total Request Live 2009," X is surrendering control and giving the crowd what it came for-literally. Fans dictate the set list by logging on to www.xtheband.com and voting for their favorite songs. Letting a band's hardcore devotees curate the gigs could get ugly for casual fans-bring on the obscurities and B-sides-but this Baltimore show remained meat-and-potatoes, heyday X: darkly enigmatic but consistently tuneful, like some brash, sonorous reinvention of American roots music. (The tour title, a stale reference to the defunct MTV show, is one of the band's few concessions to middle age. At one point, Doe jokingly invoked the name of TRL's heyday host, Carson Daly, who left the program in 2002.)

From the go-to opener, "Your Phone's Off the Hook, But You're Not," a clinic in punk-rock riff writing, everything was clearly in working order. Just days before this concert, Cervenka released a statement saying she was diagnosed with multiple sclerosis, but she looked and sounded inspired. (Tickets to the TRL tour are also available via an online auction to benefit Victoria Williams' Sweet Relief organization.) The dissonant vocal counterpoint Cervenka shares with Doe-which hit a sinister fever pitch on "Adult Books"-was as delightfully skewed as ever, and the former married couple's artistic chemistry continues to shoot sparks, even if the relationship has long evolved out of the romantic intensity. (Remember that stunning bit where they shared a microphone and sang on what looked like the verge of a deep kiss? Don't expect that.) An acoustic duet on the Dave Alvin-penned "4th of July" laid bare how potent and empathic their tandem remains, and how successfully Doe has morphed from punker to roots troubadour. (For California punks, that's become a common transformation: The Adolescents' Steve Soto opened the evening with surprisingly polished, hook-filled roots and heartland rock.)

And then there's Billy Zoom. Punk rock wasn't designed for guitar heroism, but Zoom sounded glorious: His rhythm playing was a study in muscular understatement, and his curt solos borrowed deftly from rockabilly and early rock and roll. On "Los Angeles" Zoom's surging, palm-muted accompaniment infused a common punk-guitar technique with staunch, machinelike precision; on "Johny Hit and Run Pauline," his intro and solo took the Chuck Berry lexicon into fiery sonic terrain. All sorts of players have wed punk and rockabilly since Zoom, with too many of them shrouding punk ineptitude with pompadours and sailor tattoos. When Zoom noodled before the set began, a few bars of Scotty Moore gallop were a reminder that he cut his teeth with Gene Vincent. The guitarist's hammy stage affectation-leather jacket, plastic smile, eye contact with individual audience members-has maintained its ability to bust up the audience while creeping it out.

That sort of duality defines this band: esoteric but appealing like pop, modern but indelibly linked to Americana. X is a group of likable personalities who also happen to be unrelenting cynics-in the songs, even in the stage banter. Doe, who grew up in Baltimore, recast the touristy Inner Harbor as the "Inner Horrible" and pined for the days when the bars of nearby Fells Point hosted sailors rather than frat boys. Some punks never hang it up.