But Hammond, 43, said they're not selling fans short. Instead, GLO tries to re-create Zeppelin's studio recording in a live concert situation playing songs that Zeppelin recorded, but might not have played live on stage.
Do the guys ever fear something will get lost in translation?
"Not really, because we're real sticklers for detail," Hammond said.
They're pretty meticulous, as Hammond described it. One song might take as much as 20 hours for the guys to analyze before it sounds as precise as they'd like. Hammond said the hardest songs to study were "The Rain Song," because of its modal tuning, and "Kashmir," because of its nonstandard structure.
Part of the reason is that they're not just playing what they hear, Hammond said.
They adapt their instruments to the tone that's played within the song, which might mean buying a guitar that will only be used on that one song.
So if a guitar sounds more like a Fender with a single-coil pickup?
"That's what we'll use," Hammond said. "We've actually gone as far as researching actually what they did use on each song and then we'll use that same type of guitar."
For example, Hammond said "All My Love," off Zeppelin's "In through the Out Door," uses a B-Bender Telecaster guitar. Hammond said he bought it just for that song.
"The only way to make it sound that way is to use that type of guitar," he said.
GLO formed in early 2004 when three of the bandmates - all named Paul - decided to fuel their Led Zeppelin-cover habit by starting a tribute band. They later brought on three more members and have been making a career for themselves ever since. They decided from the onset that they didn't want to go the "impersonation" route.
"I don't know if you've seen pictures of us or not, but we're already '70s rock guys - that's what we grew up with," Hammond said. "So we're already convincing in our own right."
Hammond started playing guitar at age 8. His father taught him blues tunes on a classical-style, nylon-string guitar. The boy was brought up on jazz technique and learned how to sight-read starting at age 12, when he began formal lessons.
His dad had Led Zeppelin on a reel-to-reel. But Hammond said that, when he was a boy, he was a bigger fan of The Beatles.
"The Beatles I loved as a child because they always seemed very friendly to me and I could envision them as my friends," Hammond said.
But his initial impression of Led Zeppelin?
"It kind of scared me," Hammond said. "I didn't really get it and I didn't know how to like it as a child. Until I got to be older, pre-teen, I was listening to it with other rock, I thought, 'This is some of the best rock.' I kind of latched onto it."
Hammond said he grew up during a time of the big guitar icons, Led Zeppelin being one of many. But now, tribute bands such as Dark Star Orchestra, a Grateful Dead tribute act, and The Pink Floyd Experience are growing more popular, earning similar salaries as original musicians. Some music writers are calling them "mock stars," a term Hammond says he's not very fond of.
Members of GLO have their own recording studio outside of Philly, where they master recordings for other regional artists. GLO members also have their own side projects, cranking out original tunes here and there at concerts.
But will there ever be another guitar hero of times past? The answer might be the reason why so many tribute bands are able to thrive.
"I'm leaning toward no, but hoping for yes," Hammond said.
If you go ...
WHAT: Get the Led Out, Led Zeppelin tribute band performs
WHEN: 8 p.m. Saturday, May 16
WHERE: The Maryland Theatre, 21 S. Potomac St., downtown Hagerstown
COST: $24.50 to $45.
MORE: For tickets, go to www.mdtheatre.org. To learn more about Get the Led Out, visit go to www.GLOrocks.com.