There's no question Led Zeppelin IV is one of the most iconic rock albums ever recorded.

Since its release way back in 1971, the album continues to be one of the top-selling albums, year after year (more than 37 millions copies sold worldwide).

Guitarist Jimmy Page, who produced it, vocalist Robert Plant, bassist John Paul Jones and drummer John 'Bonzo' Bonham needed only four months in the studio to produce the piece that catapulted them into the stratosphere among the biggest rock stars in the world.

In late Nov. 1970, the band set themselves up at Headley Grange (after a recommendation on the place from Fleetwood Mac), on old three-story poorhouse in Hampshire, U.K. that was built in 1795. The band brought in the Rolling Stones mobile studio and engineer Andy Johns to handle the sounds, since he was familiar with the mobile truck setup after working with the Stones. They also worked on a few songs, including "Black Dog" at Island Studios in London.

The house had no distractions and the band was under no pressure to finish in a specific time period, so the working conditions were ideal and the finished product reflects that.

Jimmy Page told BBC's "Classic Albums" that the band members would sit around and ask if Jones had anything to contribute songwise, because, up to that time, it was Page and Plant bringing forth most of the ideas and pieces for songs.

"We were always trying to encourage him to come up with bits and pieces so to speak, cause that's usually what they were, he never came up with a complete whole song or anything, (until 'In Through the Out Door')," Page told BBC. "But he had this great riff with "Black Dog" and I added some sections to it as well, and then we had the idea actually, I must be totally honest, I suggested, how you get the breaks with the vocals. That's it, I've finally owned up as no one else will in the band, but that was the idea to give it the vocal thing then the riffs in."

All of the basic tracks were recorded at Headley Grange, while Page added guitar overdubs in Ireland.

"We had the drums in the hall and sometimes the drums were in the room as well, (in the sitting room with the fireplace) and the amplifiers were all over," said Page. "When Bonzo was in the hall, Jones and I were out there with earphones, the two sets of amps were in the other rooms and other parts such as cupboards and things. A very odd way of recording, but it certainly worked. When you've got the whole live creative process going on, that's how things like "Rock and Roll" come out."

Certainly the drum sound on the record is phenomenal and "Rock 'N Roll" was recorded in a couple of takes, showing how in sync the band was at the time.

Capturing Drums on "When the Levee Breaks"

The now-famous drums from "When the Levee Breaks" came about from an idea Page and Johns had at Headley.

"Having worked in the studios for so long as a session player, I had been on so many sessions where the drummer was stuck in a little booth and he would be hitting the drums for all he was worth and it would just sound as though he was hitting a cardboard box," said Page. "I knew that drums would have to breath to have that proper sound, to have that ambiance. So, consequently we were working on the ambiance of everything, of the instruments, all the way through. I guess this is the high point of this album. You've got something like "When the Levee breaks" which was with Bonzo in the hall and on the second landing was a stereo mike and that's all there was."

Songs like "Going to California" and "Misty Mountain Hop" came together fairly quickly out of the band noodling around on different chords.

While many of the songs came easily, "Four Sticks" was a labour of love that took some time until it was up to snuff for Page. He tells a great story of how it was finally finished and how the song got its title.

"We tried that on numerous occasions and it didn't come off until the day Bonzo, who was just playing with two sticks on it and we tried all different things, then one day he picked up two sets of sticks, so he had four sticks, and we did it," said Page. "That was two takes, but that was because it was physically impossible for him to do another. I couldn't get that to work until we tried to record it a few times and I just didn't know what it was and I still wouldn't have known what it was. We probably would have kicked the track out, but then Bonzo went - and I'm not going to repeat the language he said at the time, but it was nothing to do with the fact that it was taking a long time. We had actually gone in to try on a fresh occasion and he just picked up the four sticks and that was it."

Jones had brought a mandolin to the house and Page would play around with it (having never played the instrument before) and ended up with "Battle of Evermore", a track featuring additional vocals by folk singer Sandy Denny, who Plant recommended come in and add her vocal styling to the song.

For the most popular song on Led Zeppelin IV, "Stairway to Heaven", Page had to purchase that famous Gibson SG doubleneck, so he could do all the guitar parts on one instrument.

Once he had the idea for "Stairway", he said it was a bit of a chore getting the rest of the band into it.

"It may not make a lot of sense, but it was actually quite a complicated song to get across to everybody," said Page.

"I know one of the bits that was difficult for Bonzo at the time was the twelve string fanfare into the guitar solo and that took a bit of time," recalled Page. "We were going over and over it from the beginning to the end quite a few times, with Robert sitting on the stool listening and he must have got inspiration as he wrote these lyrics then. He said I think I've got some things for it. We had an old Revox tape recorder at that time and I remember there were a good 70 to 80% of the lyrics there."

The band was sued in 2014 by 1960s band Spirit for allegedly plagiarizing "Stairway" from their song "Taurus". However last year during the much-publicized trial, a jury quickly found Zeppelin did not lift anything from "Taurus".

First Mix of Zeppelin IV Goes Wrong

The record was first initially mixed at Sunset Studios in LA with Johns. But the mix was terrible, despite Johns having good luck there mixing albums for the Rolling Stones.

"As it turned out, mixing the album was an absolute disaster," said Johns in an interview on musicradar.com. "It all sounded great at Sunset, but the only mix that got used was When The Levee Breaks. That, for some reason turned out alright. But we did this playback at Olympic Studios in London and it wasn't the greatest place to hold a playback session. I should have chosen Island. Anyway the first song goes by and it doesn't sound very good at all. Jimmy and I are sitting on the floor with heads in our hands going 'What the hell is this?' Then we played the next one and the next one… and it all sounded 'orrible."

So, basically, the album had to be mixed a second time at Island Studios, delaying the release until November, 1971. And Johns never worked with Zeppelin again after that.