The song remains the same, as Led Zeppelin once observed. But Zeppelin fans can visit the band's music anew thanks to a film of the rock titans' last show together in 2007.
That was the band's first full show in 27 years. Singer Robert Plant, guitarist Jimmy Page and bassist John Paul Jones got together again Friday to promote the film -- but that may be as close as fans will get to a new reunion.
At a news conference, the members flatly declined to answer when asked if they were tempted to perform together as Led Zeppelin.
Plant said that even lining up onstage to answer questions -- "like a bunch of soccer managers being interviewed after a match" -- was not his idea of fun.
The band members have moved on, with Plant in particular finding success in other genres. He has played with musicians from Mali and won a Grammy in 2009 for his rootsy collaborations with bluegrass musician Alison Krauss.
And, the 64-year-old singer admitted: "I struggle with some lyrics for particular periods of time" -- particularly for the famously cryptic "Stairway to Heaven."
He's not alone. Many listeners find that Zeppelin lyrics range from mystical to unintelligible.
"Maybe I'm still trying to work out what I was talking about," Plant said.
But the musicians are proud of the December 2007 show at London's 02 Arena captured in director Dick Carruthers' crisp and energetic concert film "Celebration Day."
The concert, attended by 18,000 ticket-holders selected from more than 1 million applicants, was a tribute to Atlantic Records founder Ahmet Ertegun, an early mentor of the band.
Onscreen, the 1970s hard rock heroes -- joined by Jason Bonham, son of original drummer John Bonham -- look relaxed and sound confident as they power through hits including "Kashmir," "Dazed and Confused," "Whole Lotta Love" and -- of course -- "Stairway to Heaven."
Four decades after they fused blues, R&B and rock `n' roll into a new kind of hard rock, they remain very much the 1970s rock gods -- Plant the strutting frontman, Page the gurning guitar god, Jones the unshakeable bass player.
Their chemistry is obvious, even though Plant says they don't see each other much these days. Led Zeppelin disbanded after the death of drummer John Bonham, who choked on vomit in 1980 at the age of 32.
Plant said that diving back into the band's music for the concert had been "a spectacular experience."
"To get through it and come out the other side was something not much short of miraculous," he said.
Plant said having Jason Bonham join the band for the show was "strange and it was peculiar at times" -- but also wonderful.
Page said Jason Bonham's "encyclopedic knowledge" of Led Zeppelin had been invaluable.
"Jason was absolutely monumental," the 68-year-old guitarist said. "From the very first rehearsal right through to the O2."
Led Zeppelin's resistance to reforming the band -- despite the vast sums on offer -- is the mark of a group unwilling to dwell too much in its own past.
Plant said that like the early Delta bluesmen who inspired him, Led Zeppelin is "from another time."
Rock behemoths like Led Zeppelin were blown from the charts by punk -- "I think we were ousted by the Cockney Rejects in 1977 for being a bit long-winded," Plant said -- before being rediscovered by new generations.
"Celebration Day" is released in 1,500 theaters around the world Oct. 17 and on DVD and other formats Nov. 19. No future Led Zeppelin projects have been announced.
But you never know. Jones, 66, laughed off a question about why there had been a five-year gap between the concert and the film.
"Five years -- that's five minutes in Zeppelin time," he said.