Math rock is a style of indie rock that emerged in the late 1980s in the United States, influenced by post-hardcore, progressive rock bands such as King Crimson and 20th century minimal music composers such as Steve Reich. Math rock is characterized by complex, atypical rhythmic structures (including irregular stopping and starting), counterpoint, odd time signatures, angular melodies, and extended, often dissonant, chords. It bears similarities to post-rock.
Whereas most rock music uses a 4/4 meter (however accented or syncopated), math rock frequently uses non-standard time signatures such as 7/8, 11/8, or 13/8, or features constantly changing meters based on various groupings of 2 and 3. This rhythmic complexity, seen as mathematical in character by many listeners and critics, is what gives the genre its name.
The sound is usually dominated by guitars and drums as in traditional rock, and because of the complex rhythms, the drums section of math rock groups tend to be more salient than in other genres. It is commonplace to find guitarists in math rock groups using the tapping method of guitar playing, and loop pedals are occasionally incorporated, as by the band Battles. Guitars are also often played in clean tones more than in other upbeat rock songs, but some groups also use distortion.
Lyrics are generally not the focus of math rock; the voice is treated as just another sound in the mix. Often, vocals are not overdubbed, and are positioned low in the mix, as in the recording style of Steve Albini, or the legendary Rolling Stones producer Jimmy Miller. Many of math rock's most famous groups are entirely instrumental such as Don Caballero or Hella, though both have experimented with singing to varying degrees.
The term math rock has often been passed off as a joke that has developed into what some believe is a musical style. An advocate of this is Matt Sweeney, singer with Chavez, who themselves were often linked to the math rock scene.
A significant intersect exists between math rock and emo, exemplified by bands such as Sweep the Leg Johnny or American Football, whose sound was described as "twinkly, mathy rock, a sound that became one of the defining traits of the emo scene throughout the 2000s."
The Canadian punk rock group Nomeansno (founded in 1979 and active as of 2015) have been cited by music critics as a "secret influence" on math rock, predating much of the genre's development by more than a decade. An even more avant-garde group of the same era, Massacre, featured the guitarist Fred Frith and the bassist Bill Laswell. With some influence from the rapid-fire energy of punk, Massacre's influential music used complex rhythmic characteristics. Black Flag's 1984 album My War also included unusual polyrhythms.
Bands such as Because of Ghosts, The Sinking Citizenship, and My Disco emerged in the early 2000s in Melbourne.
The European math rock scene started in the late 90s to early 2000, including bands such as Adebisi Shank (Ireland), Kobong (Poland), The Redneck Manifesto (Ireland), Three Trapped Tigers and This Town Needs Guns (United Kingdom) and Uzeda (Italy). Foals (England) was formed in 2005.
The most significant Japanese groups include Ruins, Zeni Geva, Boredoms, Aburadako, Tricot and Doom. Yona-Kit is a collaboration between Japanese and U.S. musicians. Other Japanese groups which incorporate math rock in their music include Ling Tosite Sigure, Toe, Zazen Boys, Lite and mouse on the keys. Skin Graft Records and Tzadik Records have released Japanese math rock albums in the United States.
The city of Pittsburgh is home to Don Caballero—whose drummer, Damon Che, is also involved with the international math rock band Bellini as well as Black Moth Super Rainbow, Tabula Rasa, and Knot Feeder. Bands from Washington, D.C. include The Dismemberment Plan, Shudder to Think, Hoover, Faraquet, 1.6 Band, Autoclave, later Jawbox, and Circus Lupus. The Richmond, VA-based Breadwinner inspired bands such as Fulflej and Lamb of God. Polvo of Chapel Hill, North Carolina is often considered math rock, although the band has disavowed that categorization.
In California, math rock groups from San Diego include Upsilon Acrux, Drive Like Jehu, Antioch Arrow, Tristeza, No Knife, Heavy Vegetable and Sleeping People. Northern California was the base of Game Theory and The Loud Family, both led by Scott Miller, who was said to "tinker with pop the way a born mathematician tinkers with numbers." The origin of Game Theory's name is mathematical, suggesting a "nearly mathy" sound cited as "IQ rock."
By the turn of the 21st century, most of the later generation bands such as Sweep the Leg Johnny had disbanded and the genre had been roundly disavowed by most bands labeled with the "math rock" moniker. Bands in the late 90's and 2000s, such as This Town Needs Guns and American Football, began combining Math rock and Emo, creating a much more vocally oriented sound.
In the mid-2000s, many math rock bands enjoyed renewed popularity. Slint and Chavez embarked on reunion tours, while Shellac toured and released their first album in seven years. Don Caballero reunited with a new lineup and released an album in 2006, while several of its original members joined new projects, such as the band Knot Feeder.