Grunge - aka Seattle Sound - is a subgenre of alternative rock that emerged during the mid-1980s in the Seattle area. Inspired by hardcore punk, heavy metal and indie rock, grunge is generally characterized by heavily distorted electric guitars, contrasting song dynamics, and apathetic or angst-filled lyrics. Among the most popular bands of the grunge rock era are Alice in Chains, Nirvana, Pearl Jam, and Soundgarden. The grunge aesthetic is stripped-down compared to other forms of rock music, and many grunge musicians were noted for their unkempt appearances and rejection of theatrics.

The early grunge movement coalesced in the late 1980s around an independent record label in Seattle named Sub Pop. Grunge became commercially successful in the first half of the 1990s, due mainly to the release of Nirvana's Nevermind and Pearl Jam's Ten. The success of these bands boosted the popularity of alternative rock and made grunge the most popular form of hard rock music at the time. However, many grunge bands were uncomfortable with this popularity. Many grunge bands are still active today and their influence continues to impact modern rock music.

Grunge's sound partly results from Seattle's isolation from other music scenes. As Sub Pop's Jonathan Poneman noted, "Seattle was a perfect example of a secondary city with an active music scene that was completely ignored by an American media fixated on Los Angeles and New York." Mark Arm claimed that the isolation meant, "this one corner of the map was being really inbred and ripping off each other's ideas." Grunge evolved from the local punk rock scene, and was inspired by bands such as The Fartz, The U-Men, 10 Minute Warning, The Accüsed and the Fastbacks. Additionally, the slow, heavy, and sludgy style of the Melvins was a significant influence on the grunge sound.

Outside the Pacific Northwest, a number of artists and music scenes influenced grunge. Alternative rock bands from the Northeastern United States, including Sonic Youth, Pixies, andDinosaur Jr., are important influences on the genre. Through their patronage of Seattle bands, Sonic Youth "inadvertently nurtured" the grunge scene, and reinforced the fiercely independent attitudes of its musicians. The influence of the Pixies on Nirvana was noted by Kurt Cobain, who commented in a Rolling Stone interview that he "connected with the band so heavily that [he] should be in that band." Nirvana's use of the Pixies' "soft verse, hard chorus" popularized this stylistic approach in both grunge and other alternative rock subgenres.

A number of grunge bands have reunited in recent years, including Soundgarden, Alice In Chains, Stone Temple Pilots, and Hole. This caused grunge to have a resurgence in popularity. Pearl Jam have remained active since their inception, even while their peers were inactive; in 2006 Rolling Stone writer Brian Hiatt described Pearl Jam as having "spent much of the past decade deliberately tearing apart their own fame." He further noted that the band developed a loyal concert following akin to that of the Grateful Dead. Despite Nirvana's demise, the band has continued to be successful posthumously. Due to the high sales for Kurt Cobain's Journals and the band's best-of compilation Nirvana upon their releases in 2002, The New York Times argued that Nirvana "are having more success now than at any point since Mr. Cobain's suicide in 1994.