They were there for "year zero," when punk rock was considered a danger to the British empire, yet 35 years later, their most famous album cover adorned a Royal Mail postage stamp.

The Clash, London Calling.

The Only Band That Matters' third album not only featured two of their best known tracks (the title cut and "Train in Vain"), but also that cover: Lanky Paul Simonon caught in a blur, slamming his Fender Precision bass against the stage.

That photo was taken at New York City's Palladium on September 20, 1979, just three months prior to the album's release. Photographer Pennie Smith didn't care for the shot, thinking it too blurry, but the Clash were blurry. Joe Strummer literally vibrated on stage, voice on the edge of cracking, the band chugging along like an amphetamine-fueled cheetah.

That song, by the way, isn't a Clash song despite its presence on London Calling. "Brand New Cadillac" dates to 1959, when it was first recorded by Vince Taylor and his Playboys.

The Clash weren't alone in their respect for early rock 'n' roll. The Buzzcocks' Steve Diggle told us in a recent interview that punk was about getting back to rock's roots: "Little Richard sweating in some suit, and the lights on him. It was like, wow, this is rock ‘n roll," he said.

The Reverend Horton Heat broke it down for us even better:

My perception of it was instead of looking at the attitude and the dress and the culture of punk, I break it down into more of musically technical things. From the ‘50s, you had Jerry Lee Lewis and Little Richard pounding straight eights on the piano and Chuck Berry going straight eights on the guitar. After it died out, somewhere in the era where the Beatles went psychedelic, you didn’t really have much rock and roll. You had this kind of rock, or blues rock, or whatever.

When punk rock came in, those Ramones songs are straight eights. Rhythmically, breaking it down. Punk rock was a way for rock and roll to come back.

Even nasty old Sid Vicious covered the great Eddie Cochran:

Which brings us back to London Calling's album cover. The design wasn't new -- pink and green lettering framing a black and white photo -- in fact, it dated to 1956, when Elvis Presley's debut album was released.

RCA

The Elvis sleeve captures the musician in an act of creation -- we can almost hear the song he's playing. The Clash sleeve captures a moment of destruction, Simonon beating his guitar against the stage. Are the band putting the closing bookend on rock and roll by destroying the old to make way for the new?  Or are they satirizing the image of Presley that seemed so dangerous in '56 but so tame by '79?

That's the language of criticism, that post facto exercise in meaning and interpretation. The simple truth is readily available from the people who were there. Ray Lowry, who designed London Calling's sleeve, tells his version in Thorgerson's and Powell's 100 Best Album Covers:

Most informed observers [understand] that it was a genuine homage to the original, unknown, inspired genius who created Elvis Presley’s first rock ‘n’ roll record and that it was not a calculated rip off.

The obvious thing to do seemed to bring it all back home and make plain the obvious sources of all our insanities by dovetailing it into the grand design. I had picked up a battered old copy of Elvis’s album in Chicago and I did a couple of roughs in various hotel rooms before doing the finished artwork … in the CBS Records’ art department in Los Angeles.

Nods to Elvis and the "unknown, inspired genius" behind his first album cover aside, there's still the matter of Pennie Smith's photo of Paul Simonon. Few images better capture the energy and ethos of punk. Simonon told Thorgerson and Powell the story behind the picture:

The show had gone quite well that night, but for me, inside, it just wasn't working well, so I took it out on the bass. If I'd been really smart I would have got the spare bass out, as it wasn't as good as the one I smashed up. When I look at [the album cover] now I wish I'd lifted my face up a bit more.

So the people behind the scenes weren't trying to do any of the things that people like to attribute to them. Pennie Smith wasn't taking a blurry photograph to capture some grungy punk ethos -- she simply wasn't prepared for Paul Simonon to smash a bass so close to her wide angle lens. Ray Lowry wasn't trying to design a cover that implied that the Clash were destroying the old to ring in the new -- he was just paying homage to a cool album cover design. And Paul Simonon? He just wishes he'd gotten his face into the picture and not ruined his good bass.

But this is why sometimes we have to protect the art from the artist. Regardless of what their intentions were, the team behind London Calling's cover chose this iconography. What story it tells is up to the viewer, but when one considers that the album was originally titled The New Testament, a "breaking with the old and ringing in the new" interpretation seems appropriate.

Today, the album cover is perhaps better known than the music it contains. Aside from the aforementioned postage stamp, the sleeve regularly pops up on "greatest album covers of all time" lists. Q magazine once named the picture photographer Smith didn't want used the greatest rock photo of all time. Simonon's shattered bass resides in the Rock and Roll Hall of Fame, where it looks much cooler than the "spare bass" might have.

The real test of influence is imitation, though, and countless punk album covers, posters and book covers have been inspired by London Calling over the last 35 years. Much like Never Mind the Bollocksall one needs to do to invoke "punk" is copy the album's sleeve. It's a trick so reliable that even former Clash guitarist Mick Jones gave it a shot for the cover of Big Audio Dynamite'sF-Punk.

MCA

And speaking of Mick, let's leave you with one of his (and London Calling's) finest moments: