quality:correction, stylistic:style_transfer
Style

Nirvana's musical style has been mainly described as grunge, alternative rock, and punk rock. They have also been labeled as hard rock. Characterized by their punk aesthetic, Nirvana often fused pop melodies with noise. Billboard described their work as a "genius blend of Kurt Cobain's raspy voice and gnashing guitars, Dave Grohl's relentless drumming and Krist Novoselic's uniting bass-work that connected with fans in a hail of alternately melodic and hard-charging songs".

Cobain described Nirvana's initial sound as "a Gang of Four and Scratch Acid ripoff". When Nirvana recorded Bleach, Cobain felt he had to fit the expectations of the Sub Pop grunge sound to build a fanbase, and suppressed his arty and pop songwriting in favor of a more rock sound. Nirvana biographer Michael Azerrad argued, "Ironically, it was the restrictions of the Sub Pop sound that helped the band find its musical identity." Azerrad stated that by acknowledging that they had grown up listening to Black Sabbath and Aerosmith, they had been able to move on from their derivative early sound.

Nirvana used dynamic shifts that went from quiet to loud. Cobain sought to mix heavy and pop musical sounds, saying, "I wanted to be totally Led Zeppelin in a way and then be totally extreme punk rock and then do real wimpy pop songs." When Cobain heard the Pixies ' 1988 album Surfer Rosa after recording Bleach, he felt it had the sound he wanted to achieve but had been too intimidated to try. The Pixies' subsequent popularity encouraged Cobain to follow his instincts as a songwriter. Like the Pixies, Nirvana moved between "spare bass-and-drum grooves and shrill bursts of screaming guitar and vocals". Near the end of his life, Cobain said the band had become bored of the "limited" formula, but expressed doubt that they were skilled enough to try other dynamics.

Cobain's rhythm guitar style, which relied on power chords, low-note riffs, and a loose left-handed technique, featured the key components to the band's songs. Cobain would often initially play a song's verse riff in a clean tone, then double it with distorted guitars when he repeated the part. In some verses, the guitar would be absent to allow the drums and bass guitar to support the vocals, or it would only play sparse melodies like the two-note pattern used in "Smells Like Teen Spirit". Cobain rarely played standard guitar solos, opting to play variations of the song's melody as single-note lines. Cobain's solos were mostly blues-based and discordant, which music writer Jon Chappell described as "almost an iconoclastic parody of the traditional instrumental break", a quality typified by the note-for-note replication of the lead melody in "Smells Like Teen Spirit" and the atonal solo for "Breed". The band had no formal musical training; Cobain said: "I have no concept of knowing how to be a musician at all whatsoever... I couldn't even pass Guitar 101."

Grohl's drumming "took Nirvana's sound to a new level of intensity". Azerrad stated that Grohl's "powerful drumming propelled the band to a whole new plane, visually as well as musically", noting, "Although Dave is a merciless basher, his parts are also distinctly musical—it wouldn't be difficult to figure out what song he was playing even without the rest of the music".

Until early 1992, the band had performed live in concert pitch. They began tuning down either a half step or full step as well as concert pitch. Sometimes all three tunings would be in the same show. By the summer of that year, the band had settled on the half step down tuning (E♭). Cobain said, "We play so hard we can't tune our guitars fast enough". The band made a habit of destroying its equipment after shows. Novoselic said he and Cobain created the "shtick" in order to get off the stage sooner. Cobain stated it began as an expression of his frustration with previous drummer Channing making mistakes and dropping out entirely during performances.