Jimmy Page on the rehearsal tape that captures the early magic of Stairway to Heaven

In 2016, Classic Rock readers voted Jimmy Page ’s Stairway To Heaven solo the greatest guitar ever, but the Led Zeppelin maestro was somewhat cautious about accepting the plaudits.

"Is Stairway To Heaven my best Zeppelin guitar solo?" he asked Classic Rock , before answering his own question. “No, but it’s pretty damn good. If everyone else says it’s my best solo then that’s great, that’s good, but there are others that I prefer."

More than 30 years previously, he'd been a little more more effusive. In the 1983 book The Guitar Greats , in which the BBC's John Tobler and Stuart Grundy interviewed the likes of Jeff Beck , Eric Clapton , BB King , Ritchie Blackmore, Pete Townshend, Ry Cooder, Steve Miller, Carlos Santana, Joe Walsh and Brian May, Page explained how Stairway distilled everything that made the band great.

"That really sums it all up," says Page. "It's just a glittering thing, and it was put together in such a way as to bring in all the fine points, musically, of the band, in its construction."

Page then gave an insight into how Robert Plant approached the song as the band rehearsed at Headley Grange, the former workhouse where Led Zeppelin IV was famously recorded.

"When it came to the point of running it down with Robert, there's actually a first rehearsal tape of it, and sixty per cent of those lyrics, he came in with off the cuff-that was amazing."

The tape of the session, which was uploaded to the Led Zeppelin Rarities YouTube account more than three decades later, demonstrates Page's point perfectly. You can hear Plant feeling his way around the melody, inserting words as placeholders, and resorting to "la-laa-laaaaas" where lyrics don't yet exist.

Elsewhere, Page can be heard improvising on what he's already written, painstakingly working his way towards what will become one of the most famous solos in rock'n'roll, and perhaps his defining musical statement.

"I wanted to try this whole building towards a climax, with John Bonham coming in at a later point, an idea which I'd used before, to give it that extra kick. Then there's this fanfare towards the solo, and Robert comes in after that with this tremendous vocal thing.

"At the time, there were quite a few guitars overlaid on that, and I must admit I thought – I knew – it was going to be very difficult to do it onstage, but we had to do it, and I got a double-necked guitar to approach it. We were doing a tour in the States, and we'd worked this song in, and I remember we did it in L.A. and got a standing ovation at the end of it."

A classic had been born.