To some bands, imitation is the sincerest form of flattery

In 1982, the year when Beatles fan William Gross was born, Paul McCartney hit No. 1 with "Ebony and Ivory." George Harrison released his "Gone Troppo" album, and Ringo Starr had just portrayed an uncommonly bright Neanderthal who discovers fire, invents the wheel, and fends off a Yeti in "Caveman," a movie that makes every Adam Sandler film look like "Citizen Kane."

It was evident that the solo Beatles, still mourning the loss of John Lennon, would never reunite, and Mr. Gross's generation would never see the band perform.

So, on a crisp night in Boston this past February, Gross went to see the next best thing: a Beatles tribute band.

With their eyebrows hidden behind mop fringes, the members of "1964 ... The Tribute" not only resemble the Fab Four but their renditions of songs like "I Wanna Hold Your Hand," "Love Me Do," and "In My Life" are note perfect. The band members, clad in skinny ties and funeral-parlor suits, even speak in faux Liverpudlian accents.

"I've seen footage of [the Beatles] on stage, and it really looked like them," says Gross, who is now a musician.

As rock music matures and many of its leading lights die or retire, tribute acts like "1964" are recreating the experience of seeing legendary bands for fans old and new. The burgeoning subculture drew the attention of documentarians Kris Curry and Richard Fox, whose film "Tribute" airs on Showtime Monday night at 9 p.m.

"A tribute band has its own internal rules and logic," says Ms. Curry. "Tribute bands dress like the people they're tributing. They do a lot of meticulous research about the onstage patterns, stuff like that. It's more about recreating the experience of having been to that show as opposed to just playing the songs."

The documentary follows an ersatz KISS - in white makeup, their middle-aged paunches reined in by spandex - playing songs like "Deuce" while the bass player exhales fire. Like the sight of a scraggly Bob Dylan wooing a lingerie model in the new Victoria's Secret ad, the band's act has to be seen to be believed.

Of the hundreds of tribute bands who play small venues, most are devoted to classic-rock groups with plenty of hits. With names such as Pink Voyd, Dire Fakes, Stealin' Dan, and Led Zepplica, it's easy to guess who the tribute bands are saluting. There are even a few recent artists who have spawned imitators, such as Sync In, Coldplayer, and Alanis Moreorless.

For the most part, tribute acts are motivated by hero worship. Steve Zukowsky, a Los Angeles-based guitarist, grew up wanting to be Brian May and Jimmy Page. Only, back then he could never have predicted that he would become Page in Led Zepagain, and impersonate May in Sheer Heart Attack, a Queen tribute band.

"Even though other people say, 'Oh well, you're doing other people's music, you didn't write it,' to me, it's such a part of my life," says Mr. Zukowsky, who works for an Internet company by day. "After listening to that stuff for 25 years, I don't think it's ever going to get old playing it for a few more."

While some musicians see tribute bands as a springboard to greater things, few are as fortunate as Tim "Ripper" Owens, a singer in an Ohio Judas Priest tribute band who was briefly hired by the actual band to replace their departed singer. In Curry's experience, tribute acts typically are a refuge for those who struggle with their own original material.

"As many of them said very poignantly, there comes a time in your life when you sort of take stock and say, 'The odds of me becoming a rock star over 35 are not so good,' " she says. "The guys who have their heads screwed on straight say, 'You know, this is a chance for me to perform in front of people.' "

It can be profitable, too. The Australian Pink Floyd and ABBA impersonators "Björn Again" make a living touring the world, as does "1964," which recently played Carnegie Hall. "We never intended it to be a vocation," says Mark Benson, who plays John Lennon in 1964, now in its 20th year. "I liken it to having a really, really, really long run in 'Cats.' "

It's certainly conceivable that 50 years from now, bands could still be recreating the experience of a 1977 Led Zeppelin concert, just as orchestras continue to play Bach and Beethoven. Jimmy Page certainly seems open to the idea: The guitarist personally congratulated Led Zepagain after a recent show.

Back at the "1964" show at Boston's Berklee tPerformance Center, fans certainly buy into the tribute band concept. Old friends Louis Malaquias and Dave Barry kept looking at each other during the show, each reliving the Beatlemania of their high school years. The band tries so hard to replicate the original experience that the bass player taught himself to play left-handed like McCartney.

"The only way you could come closer to [the real thing]," says Mr. Barry, "would be if you were sitting in The Ed Sullivan Show theater on Feb. 9 in 1964."