One of the most acclaimed and influential acts of the 2000s and 2010s, the Knife fused progressive sounds and viewpoints into striking electronic pop. From the beginning, Swedish siblings Karin and Olof Dreijer questioned societal and musical norms. On 2001's The Knife, they combined gender-defying pitch-shifted vocals, electronics that alluded to '80s pop and experimental techno, lyrics that explored queer perspectives, and a mordant sense of humor into subversively catchy songs, a skill they honed on 2003's Deep Cuts and its radiant single "Heartbeats." Over time, the duo's music grew darker and more ambitious. On 2006's masterpiece Silent Shout, the Knife balanced frostbitten sonics with affecting songwriting; on 2010's Tomorrow, In a Year, they helped reinvent the possibilities of opera in the 21st century. They remained fearlessly creative on 2013's final album Shaking the Habitual, culminating a body of music that inspired countless other artists to bring a razor-sharp edge to electronic music.

Karin and Olof Dreijer started making music together in mid-1999 in a small barn on the west coast of Sweden near Gothenburg. Not long before, Karin's previous group Honey Is Cool had disbanded, and they sought out the help of 17 year-old Olof with programming and production. As they collaborated, Karin's experimental pop instincts and Olof's passion for dance music and jazz combined in fresh ways. Dubbing themselves the Knife, they issued their debut single "Afraid of You," which introduced the pitch-shifted vocals and spiky electro pop they explored on their later releases, in August 2000 on their own Rabid Records label. Further sessions in Gothenburg and Stockholm completed February 2001's debut album The Knife, which added industrial textures and whimsical touches like panpipes and saxophone to the duo's sound. Acclaim for the album led to the Knife scoring the film Hannah Med H, and their pay for the project allowed Karin and Olof to quit their day jobs and focus on their music.

The Knife spent much of 2002 recording their second album, Deep Cuts. Appearing in January 2003, the album sharpened the duo's hooks and subversive politics and built on The Knife's praise, eventually reaching number 11 on the Swedish charts. The Knife were uncomfortable with the personal attention that success bought them, so they began to wear masks and boycotted the 2003 Swedish Grammis ceremony. Instead, they sent two representatives of the feminist group Guerrila Girls in gorilla masks and t-shirts emblazoned with the slogan "50/50" to collect their award for Pop Group of the Year and protest the dominance of male acts in the music industry. That year, Jose Gonzalez's cover of their single "Heartbeats'' gave them greater fame around the world.

In February 2004, a self-titled EP preceded the U.K. release of The Knife in March. Around that time, Karin and Olof Dreijer began creating their third album, first working unusual locations that included a former carbon dioxide factory and the vaults of Stockholm's Grand Church before finishing their sessions in a more conventional studio. While making the album, the Knife performed their first-ever live show in early 2005 at London's ICA, appearing with Rex the Dog (who also did a remix of González's version of "Heartbeats") and playing in front of video created for the event by artist Andreas Nilsson. His work also appeared on How I Found the Knife, a DVD/CD set that included all of the band's videos, short films, and remixes, which was released a few months later. Drawing upon childhood memories, '90s techno and trance, and Charles Burns' comic book Black Hole among other inspirations, February 2006's Silent Shout gave a moodier cast to the Knife's sound and more personal perspective to their songwriting. Along with considerable critical acclaim, the album also garnered the duo more popularity at home and worldwide: Silent Shout topped the Swedish charts, reached number 28 in the U.K., and peaked at number 12 on the Top Dance/Electronic Albums chart in the U.S. The Knife played a handful of European, Scandinavian, and North American dates in 2006, accompanied by more of Nilsson's visuals. That October, Mute reissued The Knife and Deep Cuts. At the 2007 Swedish Grammis ceremony, the Knife won six awards, including Album of the Year and Artist of the Year. That July saw the release of a deluxe edition of Silent Shout that featured a DVD and live album of the group's April 2006 performance in Stockholm as well as music videos.

Once the Knife's promotional duties for Silent Shout were completed, the Dreijers embarked on individual projects. Karin launched their solo career as Fever Ray, working with Silent Shout collaborator Christoffer Berg on 2009's self-titled debut album, while Olof issued a series of EPs of ambient techno as Oni Ayhun. Midway through these projects, the Danish theater company Hotel Pro Forma commissioned the Knife to write the music for an opera commemorating the 100th anniversary of Charles Darwin's On the Origin of the Species that would be performed at Copenhagen's Danish Royal Opera House. Working with Mt. Sims and Planningtorock, the duo recorded the music in Berlin, Stockholm, and Copenhagen over the course of 2008 and 2009. A studio version of the piece, Tomorrow, in a Year, was released in March 2010. A lengthy work featuring mezzo-soprano Kristina Wahlin, a halldorophone, and environmental sounds recorded near the Amazon river, Tomorrow, in a Year was more challenging than the Knife's previous work but still fared respectably on the charts: It reached number 24 in Sweden and peaked at number ten on the Dance/Electronic Albums chart in the States.

Later in 2010, the Knife began working on new music shaped by Olof's participation in a gender studies course as well as the writings of French philosopher Michel Foucault. Preceded by the singles "Full of Fire" and "A Tooth for an Eye," April 2013's Shaking the Habitual was an unsettling 90-minute meditation on topics including gender theory, economic inequality, and the environment. The album earned praise for its ambition and unwavering viewpoint, and was a top ten hit in Sweden. The Knife's tour in support of the album was equally ambitious, incorporating a rave-like atmosphere and elaborate choreography designed by an all-female creative team. While on tour, the duo composed the music for Europa Europa, an anti-nationalist cabaret conceived of by the Swedish art group FUL. In June 2014, they released the mini-album Shaken Up Versions, a collection of some of the band's songs as they were performed on the Shaking the Habitual tour. That November, the Knife disbanded. Karin continued to release music as Fever Ray, while Olof pursued DJing and producing. In 2020, the Knife celebrated their 20th anniversary by making their music available on streaming services. The following year, they reissued Silent Shout on vinyl and streamed a 2006 concert online. ~ Heather Phares, Rovi