Nirvana completed 20 years since the launch of Nevermind. Cobain, single-handedly, revolutionized Grunge, and the album went on to become rock's great rebirth causing a major shift in popular culture.

Here are the top 10 songs Nirvana songs that became immortal in time.

Smells Like Teen Spirit: “Smells Like Teen Spirit” is Nirvana’s opening track and lead single from their second album, “Nevermind.” Written by Kurt Cobain, Krist Novoselic, and Dave Grohl, the surprising success of Smells Like Teen Spirit in late 1991 pushed Nevermind to the top of the charts at the start of 1992, a point where alternative rock came into being.

According to Nirvana frontman Kurt Cobain: “I was trying to write the ultimate pop song. I was basically trying to rip off the Pixies. I have to admit it. When I heard the Pixies for the first time, I connected with that band so heavily that I should have been in that band—or at least a Pixies cover band. We used their sense of dynamics, being soft and quiet and then loud and hard.”

Did You Know: The lyrics to Smells Like Teen Spirit, previously, were often difficult for listeners to decipher, both due to their nonsensicality and because of Cobain's slurred, guttural singing voice.

Come As You Are: The song was the band’s second American Top 40 hit, reaching number thirty-two on the Billboard Hot 100. In 2004, Rolling Stone named it at #445 on its The 500 Greatest Songs of All Time list and placed it at #452 in the 2010 reissue.

During the harmony overdub session, Cobain accidentally sang the phrase And I don't have a gun too early, appearing the fourth time he sings the word memoria after the guitar solo. He decided to keep the mistake in the final recording.

Did You Know: In 2005, a sign was put up in Aberdeen, Washington, Cobain's hometown, that reads Welcome to Aberdeen: Come As You Are as a tribute to Cobain.

Rape Me: “Rape Me” was released as the second single from Nirvana's third album In Utero in 1993. Cobain conceived Rape Me as a life-affirming anti-rape song.

He told Spin, It's like she's saying, 'Rape me, go ahead, rape me, beat me. You'll never kill me. I'll survive this and I'm gonna fucking rape you one of these days and you won't even know it.'

Did You Know: Nirvana had wanted to play Rape Me during its performance at the 1992 MTV Video Music Awards. While MTV initially told the band they could play any song it wanted, it later insisted that the group play Smells Like Teen Spirit instead.

Lithium: “Lithium” features shifts in dynamics from quiet to loud sections, and was released as the third single from the band's second album Nevermind in July 1992.

Nirvana singer/guitarist Kurt Cobain described Lithium as one of those songs I actually did finish while trying to write it instead of taking pieces of my poetry and other things.

Cobain said the song is about a man who, after the death of his girlfriend, turns to religion as a last resort to keep himself alive. To keep him from suicide.

Did You Know: Nirvana biographer Michael Azerrad described the song's title as a reference to Karl Marx's statement that religion is the opiate of the masses.

The Man Who Sold The World: A live rendition of the song, which was originally from David Bowie, was recorded by the band in 1993 during their MTV Unplugged appearance, and it was released on their MTV Unplugged in New York album the following year.

Nirvana regularly covered the song during live sets after their memorable acoustic performance up until lead singer Cobain's death in 1994.

Did You Know: In the wake of the Nirvana cover, Bowie bemoaned the fact that when he performed the number himself he would encounter “kids that come up afterwards and say, 'It's cool you're doing a Nirvana song.'”

Sliver: Nirvana members Kurt Cobain and Krist Novoselic wrote the music to Sliver with temporary drummer Dan Peters during a practice session.

“Sliver” was released as a single in 1990 making the top 100 in the UK. The song charted in Ireland two years after release, shortly after the success of Nevermind.

Did You Know: A music video was made for Sliver as promotion for Incesticide in March 1993. The video starts with Kurt Cobain's daughter Frances Bean Cobain (who was an infant at the time) dancing to the opening bassline.

Heart-Shaped Box: The song was released as the first single from the group's third and final studio album, In Utero, in 1993.

Heart-Shaped Box received much American radio airplay, reaching number one on the Billboard Modern Rock Tracks chart.

Journalist Gillian Gaar described Heart-Shaped Box as the Nirvana formula personified, with a restrained, descending riff played through the verse, building in intensity to the cascading passion of the chorus.

Did You Know: Cobain said the song was inspired by documentaries about children with cancer. He told biographer Michael Azerrad, Anytime I think about it, it makes me sadder than anything I can think of.

All Apologies: All Apologies was the band's third number one Modern Rock hit and reached number 32 on the UK Singles Chart, and had been around since 1990. Nirvana first recorded the song during a January 1, 1991 demo session with Craig Montgomery in Seattle, Washington.

Cobain dedicated All Apologies to his wife Courtney Love and their daughter, Frances Bean Cobain. He told biographer Michael Azerrad that while the lyrics had nothing to do with his family, the song's mood (Peaceful, happy, comfort) was intended for them.

Did You Know: Like its predecessor Heart-Shaped Box, the single was not released commercially in the United States.

About A Girl: It is the first song on the posthumous MTV Unplugged in New York album from which it was a single in 1994.

In a 1993 Rolling Stone interview with David Fricke, he explained: “Even to put About a Girl on Bleach was a risk. I was heavily into pop, I really liked R.E.M., and I was into all kinds of old ‘60s stuff. But there was a lot of pressure within that social scene, the underground — like the kind of thing you get in high school. And to put a jangly R.E.M. type of pop song on a grunge record, in that scene, was risky.

Did You Know: About a Girl was written after Kurt Cobain spent an entire afternoon listening to Meet The Beatles! repeatedly.

You Know You’re Right: “You Know You’re Right” is the first song on its compilation album, Nirvana (2002), and one of the last songs recorded by the band. The song was originally written in 1993 and was one of the last known Kurt Cobain compositions.

According to a 2004 Seattle Times article by Gillian G. Gaar, it was listed as Kurt's Song #1 on the tracking sheets from the Robert Lang Studios recording session.

Did You Know: The band's lead singer and Cobain's widow, Courtney Love, introduced it as a song that Kurt wrote; [the] last song, almost.