Rock 'n' roll needed a serious fix by the last part of the '80s. Some interesting things were happening in the fringes, like within the burgeoning alternative scene, but for the most part hard rock was in a bad place by the middle of 1987.

Hair bands, synthesizers and veteran acts left over from the '60s and '70s that were desperately trying to stay relevant in an era that pretty much had no use for them had nearly ruined rock music in the years leading up to the '90s.

Then came Guns N' Roses.

They had been building buzz since 1985, when the core lineup – singer Axl Rose, guitarists Slash and Izzy Stradlin, bassist Duff McKagan and drummer Steven Adler – started to hit the clubs around their home base of Los Angeles. By 1986, their shows had attracted many of the area's major record labels, and the band signed with Geffen – which released a four-song EP, Live ?!*@ Like a Suicide, at the end of the year.

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Nobody was really ready for what came next. From August to December 1986 the band holed up with producer Mike Clink (who served as an engineer on records by Metallica, Starship and UFO) in a trio of regional studios – Rumbo, Take One and Can-Am – to work on their debut album. On July 21, 1987, Appetite for Destruction was released.

How 'Welcome to the Jungle' Changed Everything

From the stuttering opening notes that give way to the kick-start attack riff of the record's first song, "Welcome to the Jungle," it was evident that rock 'n' roll – the real stuff – was taking a dark and dangerous turn for the better. Guns N' Roses' Appetite for Destruction was a revelation; "Welcome to the Jungle" was its call-to-arms introduction summed up in four and a half career-making minutes.

The song was co-written – like most of the album's tracks – by the band, but Rose, Slash and McKagan have detailed their individual contributions to it over the years. (Not so surprisingly, the often contentious band has different opinions about some of the song's origins.) What no one doubts is that it's about Los Angeles – specifically, the "Hollywood streets," as Stradlin told Hit Parader in 1988 – and the soul-sucking effect the city has on newcomers. (Fittingly, none of the group's members was originally from L.A.) "Welcome to the jungle, we take it day by day / If you want it, you're gonna bleed but it's the price to pay," Rose sings in a voice that sounds both threatened and threatening. "Watch it bring you to your knees."

Rose has said he wrote the lyrics when he was in Seattle visiting a friend, and the difference between the two cities revealed the bloodsucking nature of his adopted home. "It's a small city compared to L.A.," he said. "It seemed a lot more rural up there. I just wrote how it looked to me. If someone comes to town and they want to find something, they can find whatever they want." Another part of the song – the breakdown that concludes with Rose's menacing "You know where you are? You're in the jungle, baby / You're gonna die" – was reportedly inspired by Rose's run-in with a homeless man in New York City who screamed those same words at him.

"For young, impressionable musicians who aspired to rock stardom, Hollywood could be as intoxicating and dangerous as it was for hot 18-year-old actress wannabes just off the bus from the Midwest," Slash noted in the book Louder Than Hell: The Definitive Oral History of Metal.

Things get a little more complicated when it comes to the music. Slash told Spin in 1999 that the earth-shaking guitar part on "Welcome to the Jungle" was "just a riff I made sitting in my bedroom on an acoustic guitar, and Axl just happened to be there. Where he got the lyrics, I really have no idea, but when we actually put the song together, I think it took maybe an hour."

In his 2007 autobiography Slash, the guitarist said the entire band expanded on that riff's basic foundation. But McKagan, in his own autobiography, 2011's It's So Easy (And Other Lies), claimed that "Welcome to the Jungle" dated back to 1978 with a song called "The Fake" that he wrote with his punk band the Vains. Slash agreed that the breakdown section came from McKagan, but there's some dispute as to what else was carried over.

Watch Guns N’ Roses’ ‘Welcome to the Jungle’ Video

A Video Cements Their Image Forever

Either way, the song's slippery groove, coupled with the ferocious guitar stabs and Rose's menacing vocal, made it an instant classic. "The song had a heavy swing to it – a dirty, nasty groove," Slash later said. "But there was also a midsection in which the band pulled back a little, easing the tension."

"It had a really cool kind of soulful feel," he noted. "There was no analyzing this stuff; writing a song was something that happened spontaneously. But in that whole discovering-ourselves period from 1985 through '86, when we were living very haphazardly and getting together and jamming, there was something going on that not a lot of people had. And this song just had this natural feel that was very cool.”

"Welcome to the Jungle" was released as Appetite's second single – following "It's So Easy," which bombed on the charts – in September 1987, but wasn't an immediate hit. (The initial pressing included a live cover of AC/DC's "Whole Lotta Rosie" on the B-side.) After "Sweet Child o' Mine" reached No. 1 almost a year later, "Welcome to the Jungle" was reissued as a single in October 1988, and this time the song rocketed into the Top 10, stopping at No. 7 and securing its legacy. (It climbed to the Top 25 in the U.K.)

Performance sections from the song's famous video – which featured Rose as an out-of-towner getting his first taste of the Los Angeles streets – pretty much summed up the Guns N' Roses experience in less than five minutes: Rose's serpentine dance, Slash's top hat, and the grimy sex-and-drugs culture that had swarmed around the band from the start are all represented.

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Sprinkled with references to A Clockwork Orange, The Man Who Fell to Earth and Midnight Cowboy, the video had trouble landing a spot on MTV – where hard-rock music was candy-colored, pop-leaning and party-all-the-time safe, far from the dark and dangerous tone of "Welcome to the Jungle" and the rest of Appetite for Destruction. But after label head David Geffen persuaded the network to show the clip late at night, it picked up steam, slowly pulling in sales for Appetite for Destruction, which finally made it to No. 1 a little more than a year after its debut.

Since then, "Welcome to the Jungle" has permeated all corners of pop culture. It's been used in commercials, to sell sports drinks, at sporting events, to tease movies, in video games and played by two guys on cellos. VH1 called it the greatest hard-rock song of all time, and it still regularly appears on best-ever songs lists (including Rolling Stone's, Q's and Pitchfork's). Guns N' Roses have played the song at almost every single concert, and for years it opened their shows.

Thanks in part to the band, rock 'n' roll slowly but surely came back around. It took a few years, and a heavier scene birthed in Seattle, but Guns N' Roses' influence on the '90s and the return to straight-on, no-frills rock music was massive. After Appetite for Destruction, rock 'n' roll got real again. The opening shot on their debut album remains a defining moment of that movement.

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