Is copy better than the original?

After a show by his band Get the Led Out, guitarist Paul Hammond encountered an older fan who asked, "You guys have been around since the '70s, right?"

The man had mistaken the band for Led Zeppelin, whose songs GTLO has made a fruitful career playing over the last five years. The distinction grows blurrier every day as the Philadelphia-area band Get the Led Out sells out bigger venues and now embarks for the first time on recording Zeppelin's mythic songbook.

"You ask, 'Why would they want to hear us do it?' " says Paul Sinclair, who sings lead. "I'm curious about that myself, but we have people coming to our shows who want us to release a DVD. They love the way that we perform these songs, which is the highest compliment ever."

A standard GTLO set includes 27 songs, album tracks only, three solid hours, breaking for an intermission only if a venue requires one. When the band last played the Keswick Theatre, older fans could be heard bragging that they saw Zeppelin back in the day and that Get the Led Out is better.

That might seem hard to believe until you witness the might and versatility of the players, who include rhythm guitarist Jimmy Marchiano, bassist Paul Piccari, drummer Adam Ferraioli, and multi-instrumentalist Andrew Lipke.

Not content to play an approximation of Zeppelin, Get the Led Out strives to re-create every last sonic detail the band committed to tape. Hammond hand-built a "gizmotron" to replicate certain sounds on "In the Evening," and went to great pains to harness the low-speed tape effects heard on "Whole Lotta Love." That's as much a part of their quest as Robert Plant's lyrics or Jimmy Page's trail-blazing guitar, and given the complexity of Led Zeppelin recordings, it's an endless one.

"That's absolutely what it is," agrees Sinclair. "We will never get there, but we'll die trying."

Both 43, Hammond and Sinclair have known each other since 1984, and have long shared a passion for the fiery, ambitious hard rock of Zeppelin and Aerosmith. Forming the band Sinclair, they played their own version of such music in the late '80s and '90s. The band garnered a sizable following, opening for Foghat and even the early Zeppelin tribute Physical Graffiti, but was often dismissed as a '70s throwback. Although it had several near-misses with major record deals, the band never reached the heights Get the Led Out has after just five years.

Before GTLO, the mainstay of the two Pauls' music life was running the esteemed Fat City Studios out of Sinclair's home in Blue Bell, where he lives with his mother and her excitable dog. Countless bands have trudged through the house en route to the basement, where the Pauls have recorded, mixed and mastered music since 2000. Fat City has never had to advertise, because it's always busy enough to thrive on referral clients only.

Mastering is what Fat City is best known for, putting its stamp on a slew of local acts - from the Brakes and Mutlu to the A-Sides and BC Camplight - and some far beyond Philadelphia. The enigmatic songwriter Will Oldham, who's based in Louisville, Ky., and records as Bonnie "Prince" Billy, has been to Fat City twice. And the Pauls recently mastered a release by the noisy Norwegian band Serena Maneesh.

Mastering is the final stage in an album's production, after recording and mixing. It includes removing unwanted noises, making the recording sound equally good in any format or playing device, and cementing all the sound levels. Employing vintage analog equipment, Hammond and Sinclair are known as much for their love of music as for their sharp ears.

Fat City is among the varied music-related work that sustained Hammond and Sinclair before Get the Led Out took off in the past year. The Pauls never suspected that when they finally could make a living playing in a band, it'd be a Led Zeppelin tribute.

"In the late '80s, Zeppelin was so passe," says Hammond. "They had just broken up, and nobody knew yet that they were going to be this huge, amazing Greatest Band of All Time." He pauses and glances over at Sinclair, who offers quietly, "I knew."

Get the Led Out has been on a steady rise, playing mainly in legitimate theaters instead of small bars. Last January the band signed with SRO, a national booking agent that handles Janis Ian, Patty Larkin and Karla Bonoff, as well as the tribute bands Pink Floyd Experience and Dark Star Orchestra.

Following sold-out shows at the House of Blues in Atlantic City and the Keswick Theatre in Glenside, GTLO is headlining Philadelphia's Electric Factory on Jan. 24 and Times Square's Nokia Theater in March.

But despite their success, and the increasing prominence of tribute bands, Sinclair and Hammond bristle at the term.

"Tribute gives you that image impersonator," says Sinclair.

Adds Hammond, "I say we're a Led Zeppelin 'reissue band.' "