What it Means:
Math-rock is a sound whose roots trace back to the American hardcore scene of the late-'80s. Wanting to employ hardcore's elements —speed, tightness, dissonance, volume— in more abstract, interesting ways, a scene developed in which bands played irregular rhythms and unconventional guitar fragments in sharp, precise ways.
Where hardcore bands, like their punk forebears, stuck to rock orthodoxy, math-rock bands took influence from uncool sources like Captain Beefheart, Henry Cow, and King Crimson; exploding familiar riffs into strange shapes. In many ways, its relationship to hardcore is similar to no-wave's relationship to punk; but, where no-wave bands championed amusicality and a complete lack of training, math-rockers held technical proficiency of importance.
The sound sprung up in midwestern US cities in the late-'80s and early-'90s, sharing its beginnings —and many of its key musicians— with the initial flourishings of American post-rock.
Bastro, whose members would go on to form key post-rock bands Tortoise and Gastr del Sol, were in many ways the first true math-rock band, and their sound —made long before math-rock began to grow into bonafide movement— is still seen as a definitive example of the genre.
How it Sounds:
Math-rock is, as its name suggests, renowned for its complexity. Where rock'n'roll is eternally stuck in 4/4 time, math-rock bands deliberately employed strange meters like 7/8 and 11/8. Bands flaunt virtuosity, not as individual players, but as a unit: stopping and starting at irregular intervals, turning on a dime and breaking in new, unexpected directions as one.
Vocals tend towards unintelligible screams or being completely absent; signature math-rock bands like Breadwinner, Don Caballero, and Hella all instrumental. Guitars don't play familiar chords, riffs, and melodies, but create repetitive patterns —often via fretboard tapping— that can often be dissonant or amelodic. And drums are, routinely, the foremost instrument in math-rock bands, the very center of a band's rhythmic sound.
Due to their close relationships, crossover of early key musicians, and tendency towards instrumentalism, there can be some confusion between post-rock and math-rock bands and sounds. But that isn't exactly a misconception about the genre itself, I suppose.
Where the Name Came From:
Like countless genre names —twee, shoegaze, krautrock— math-rock was initially invented as a term of slander, mocking the technical proficiency of its players. The name seemed such a natural fit that it seemed to have no source.
Matt Sweeney from indie-rock outfit Chavez, however, told this (possibly apocryphal) tale in an interview with Pitchfork in 2006. "It was invented by a friend of ours as a derogatory term for a band me and James [Lo] played in called Wider," said Sweeney. "His whole joke is that he'd watch the song and not react at all, and then take out his calculator to figure out how good the song was. So he'd call it math rock, and it was a total diss, as it should be."
When it broke:
Well, math-rock certainly never broke out. No math-rock band ever became famous, and the genre itself never took a strong hold on the pop-cultural consciousness.
But, if there was a time in which math-rock first became a noticeable underground movement, it was circa 1995. The genre's patron saint, Steve Albini, had become a figure of huge counter-cultural clout; from his acerbic writing in zines like Forced Exposure and English weeklies like Melody Maker, his production for bands as big as The Pixies and Nirvana, and his role out front of Big Black and Shellac.
Record labels like Touch and Go and Skin Graft were fostering rosters loaded with bands making complex, dissonant, angular guitar-rock. And a new crop of bands —US Maple, Don Caballero, A Minor Forest, etc— were furthering the idea that this was a genuine movement, that a new, fierce sound was taking hold.
Math-rock never really went beyond that; never really became anything more than a sub-strain of the underground. But if the genre had a time in the sun —a time in which future generations could look back on as its 'golden age'— it was then.
Bastro, Diablo Guapo (1989)
Breadwinner, Burner (1994)
Don Caballero, Don Caballero 2 (1995)
A Minor Forest, Flemish Altruism (Constituent Parts 1993–1996) (1996)
Hella, Hold Your Horse Is (2002)
Though it has little cultural capital as some happening movement, the sounds of the genre are alive. There's a cult community of fiercely-loyal math-rock purists sticking true to the sound —for whom a band like Japan's Lite, tastefully instrumental and post-rock-ish, are pin-ups— but far more interesting have been a recent run of bands who, whilst essentially math-rock, aren't stylistic purists, and have thus found much crossover.
Battles are essentially math-rock royalty; founded by former Don Caballero/Storm & Stress leader Ian Williams, and featuring super-tight former Helmet skinsman John Stanier. They've publicly abhorred the evocation of the old genre, but the band's dancefloor-friendly jams are built along the same old lines of repetition and complex polyrhythms.
Fang Island are, underneath their Andrew W.K-styled totally-awesome bro-down-ness, a math-rock band: all chaotic riffing at odd angles. Foals and This Town Needs Guns, a pair of bands from Oxford, England, both grew from a scene of local math-rock nerds (citing largely-forgotten US math-rockers Sweep the Leg, Johnny as key influence), but have applied the genre's elements to pop songwriting, creating a kind of math-rock/dance-punk hybrid.
Marnie Stern, the fretboard shredding guitarist from New York, has earnt plenty of critical acclaim and notoriety for, essentially, feminizing ridiculously-complex, hyper-virtuosic punk. Stern's genre credentials check out, too; she's collaborated with Zach Hill of Hella and Robbie Moncrieff of What's Up?, and toured with math-rock true-bloods Tera Melos.
And few ever refer to either band in these terms, but both idiot-savant noise-pop outfit Deerhoof and ridiculous surf-rock kids Ponytail are, in their own ways, math-rock bands; even if both acts seem to be as much about chaos as control.