Although their relevance would eventually come under fire by the likes of the Sex Pistols and The Clash, progressive-rock pioneers Emerson, Lake & Palmer, from the very start, displayed the very same kind of musical ideology that defined punk. “We were very defiant,” Keith Emerson says. “We did what we wanted. It wasn’t about having hit singles or being on the radio, although we did manage to get a lot of radio play and have singles. We listened to so much and brought it all into what we were doing.”

When the trio of Emerson, Greg Lake and Carl Palmer entered London's Advision Studios in January 1971 to begin work on their sophomore album, their debut disc was making waves as a crafty, ambitious bit of “art rock.” Pressure was on the band to make an even bigger statement statement with their follow-up, but Emerson says that Tarkus took shape with no real agenda.

“There wasn’t this grand concept or anything like that,” he says. “We’d already made the record with the dove on the front, and now we were making another with an armadillo on it. In many ways, I suppose we were still learning how to be a band."

Part of that learning curve involved playing records for one another and sharing disparate influences. Before sessions began, Emerson would drop by Lake’s apartment, where the bassist-guitarist and singer would play the keyboard ace tracks by Simon & Garfunkel, Joni Mitchell and Cannonball Adderly. “It was all very interesting,” says Emerson. “After hearing what Greg had, I’d play him some Shostakovich. Somehow, we managed to put it all together. We were pretty happy doing so.”

However, that spirit of harmony and adventure hit a wall over the 21-minute title piece, a seven-movement suite that Lake couldn’t find much joy in. “It provided for a lot of angst,” Emerson says. “Greg wasn’t too happy with it. He thought it was too much of a classical piece and that it was too similar to what I had done with The Nice. Carl liked it, though. As a drummer, Carl was always willing to face a challenge.”

Released on 14 June 1971, Tarkus was a watershed moment in the burgeoning progressive-rock movement (“we never used that term, ‘prog rock,’” says Emerson. “I don’t know where that got started”), hitting number one in the UK and reaching the Top 10 in the States. “It sounds amazing now, going number one,” says Emerson. “At the time, we couldn’t really celebrate – we were too busy. We were touring like crazy, and if we weren’t on the road, we were in the studio working on things that were even more demanding. This was a period of very intense creativity.”

Recently, Razor & Tie reissued ELP’s debut album and Tarkus as lavish three-disc sets, remixed by Porcupine Tree’s Steven Wilson, both of which contain previously unheard outtakes. On the following pages, Emerson recounts the writing and recording of the original album, a work that he sums up as “pretty incredible. You listen to the record and you go, ‘Oh, that’s them. That’s ELP.’ Seriously, I wouldn’t want to change one note.

“It offers a lot for the advancement of musicians. If anybody wants to get into progressive rock music – and God forbid anyone wants to [laughs] – it provides the elements. You’ve got a lot going on with Tarkus.”