THE LIGHTS DIM and a sinister recorded voice fills the room. "Everyone. Everyone," it repeats, louder each time. One by one, the band members walk onstage, exactly as on the just-released concert DVD U2 Vertigo Live From Chicago. Each figure is instantly recognizable: the ski-capped, goateed guitarist, the bassist with the superbaggy pants, the clean-cut blond drummer in a simple, buttoned shirt and, of course, the iconic bespectacled singer in signature black. They launch into the latest single "City of Blinding Lights," with each vibrant note faultless. The impassioned voice, the chiming guitar, the pulsing bass and the militaristic drumming evoke two decades' worth of songs you know by heart. The transcendent chorus arrives, with the singer's arm and heart extended to the crowd, "Oh, you look so beautiful, tonight!" But for some reason, the bassist is singing backup instead of the guitarist. In fact, the bassist looks too young. Come to think of it, the drummer and singer are too svelte, and the guitarist isn't svelte enough.

This isn't U2, but Zoo Station, a San Francisco tribute band self-dubbed "the complete U2 experience." The group more than deserves this title, as evinced by its song arrangements, outfits and even its stage banter, which are all replicated precisely from real U2 concerts. "Thankfully, there is no shortage of DVDs to study," says drummer Skott Bennett, also known as "Barely Larry." Forgoing genetics, the band members' resemblance to the Irish superstars is uncanny, right down to their penchant for charity (proceeds from Zoo Station T-shirt sales are donated to the Red Cross).

Most impressive, and perhaps most confounding, is Bonalmost, who eerily channels U2's lead singer, Bono. "He has a method-actor approach, getting into character hours before our show starts," states Bennett, seemingly mystified by his band mate's staunch inhabitance of the role. "The aliens dropped him off from Planet Bono," Bennett adds. "He blows our minds every week." When demonstrating his expertise in rock-star poses, it certainly is difficult to imagine him working his day job as a cook. "I'm more of a salad maker," Bonalmost tells me at intermission with a feigned Irish accent and Bono's trademark smirk.

With the recent anniversary of John Lennon's murder, this degree of devotion to a rock star may seem a little, well, creepy. But for Zoo Station—which formed through a Craigslist post in 2002—it comes from a very simple and pure place. "All four of us have been U2 fans for a very long time," Bennett explains. "I learned to play [drums] by locking myself in my room and listening to the War album." By being U2 fanatics themselves, these musicians know firsthand what's lacking in the rock star/audience dynamic. They give fans what the actual band cannot, whether it's performances of obscure songs or mere accessibility. "Instead of paying $200 bucks for floor seats, I get personal with the band," says Zoo Station fan Rodney Yeats. "I don't stand in line for 12 hours, and most importantly, I get the music."

As clichéd as it sounds, it's really all about the music, especially for those paying tribute to now-defunct bands. "Many of our fans were too young to see the Police live," reminds John Messier, drummer for the Police tribute trio Stung at night, life insurance agent by day. "Now, people have a chance to close their eyes, feel the volume and put themselves there." For many, a guaranteed night of their favorite Police songs performed by a power trio is certainly more appealing than the bloated, insipid song arrangements of Sting's solo concerts.

As ubiquitous as tribute bands, of course, is the criticism of them. Many are skeptical to support groups that use another's fame. Another point of contention is the precious stage time at venues that could be used by local artists performing their own music. But members of tribute bands identify with this side as well. This frustration is amplified by the perilous state of the music industry, where the fostering of artists has been replaced by pressure to be an immediate commercial success.

Rudy Colombini, a hotel owner and the Mick Jagger figure in the Unauthorized Rolling Stones, has lived through this predicament. Dropped from his record label when a moderate radio hit didn't translate into album sales, he found his second wind on the tribute-band circuit. "Some friends called me up to sing in a blues band," he recounts, "but I noticed I was doing the Stones doing the blues." A Rolling Stones tribute band made more sense to Colombini, one of countless people who learned about the blues through the band's cover versions. With the Stones charging upward of $450 a ticket for their recent Bay Area shows, Colombini's tribute band offers an affordable alternative with the same hit songs and a much better view of "Mick's" moves. "When you see the Stones, 95 percent of the stadium is watching a TV," he asserts. "It's the difference between [seeing] a movie and a play."

Bands who add their own twist to the tribute have been extremely well received, especially AC/DShe, an all-female tribute to early AC/DC. "There weren't any all-girl tributes around, and we thought it would be a cool juxtaposition to have girls playing these supermacho roles," explains lead singer Bonny Scott. Staying true to the no-nonsense demeanor of the Australian rockers, she's adamant that there is no feminist bent to their work. "Rock & roll should have no platform or political agenda," she says. "To attach a political agenda to AC/DC would be a travesty."

In this peculiar realm of the performing arts, the term "success" understandably takes on a slew of new meanings for the performers. "I guess doing it full time, a la Super Diamond or Bjorn Again, is the most you can hope for," says Zoo Station's Bennett, who works as an art director to pay the bills. Making a living at your craft is a goal surely all musicians share, but for some, success goes back to the objects of their obsession.

"There is one thing left that we need to achieve to truly be successful and that is to meet AC/DC," says Bonny Scott, reminding us they're fans, first and foremost. Stung's ambitions are slightly more difficult. "We vowed that we would play until the Police got back together," says Stung singer Brooks "Bee" Lundy. "Until then, we will continue to do our thing."

Doing their thing and making audiences happy is no doubt the biggest reward for tribute bands. "I look out and see someone's expression change, knowing they are reliving some meaningful moment," gushes Bennett. "If that's our legacy, you could do a lot worse."

The Unauthorized Rolling Stones play New Year's Eve at the Little Fox Theatre, 2215 Broadway, Redwood City (650.FOX.4119). Tickets are $40. Zoo Station plays Britannia Arms Downtown on Jan. 27.

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