Post-rock is a form of experimental rock characterized by the influence and use of instruments commonly associated with rock, but using rhythms and "guitars as facilitators of timbre and textures" not traditionally found in rock. Post-rock bands are often instrumental.
Sigur Rós, Godspeed You! Black Emperor, Stereolab, Mogwai, Explosions in the Sky, Don Caballero and Tortoise are among the more prominent bands described as post-rock, but their styles are very different, despite being instrumental bands cantered on guitars and drums.
The term "post-rock" is believed to have been coined by critic Simon Reynolds in his review of Bark Psychosis' album Hex, published in the March 1994 issue of Mojo magazine, however earlier uses of the term have been found.
The term was used by American journalist James Wolcott in a 1975 article about musician Todd Rundgren, although with a different meaning. It was also used in the Rolling Stone Album Guide to name a style roughly corresponding to "avant-rock" or "out-rock".
Another pre-1994 example of the term in use can be found in an April 1992 review of 1990s noise-pop band The Earthmen by Steven Walker in Melbourne music publication Juke, where he describes a "post-rock noisefest".
The post-rock sound incorporates characteristics from a variety of musical genres, including krautrock, ambient, prog rock, space rock, math rock, tape music, minimalist classical, British IDM, jazz (both avant-garde and cool), and dub reggae, as well as post-punk, free jazz, contemporary classical, and avant-garde electronica.
Post-rock compositions often make use of repetition of musical motifs and subtle changes with an extremely wide range of dynamics. Typically, post-rock pieces are lengthy and instrumental, containing repetitive build-ups of timbre, dynamics and texture.
Vocals are often omitted from post-rock; however, this does not necessarily mean they are absent entirely. When vocals are included, the use is typically non-traditional: some post-rock bands employ vocals as purely instrumental efforts and incidental to the sound,
Wider experimentation and blending of other genres have recently taken hold in the post-rock treescene. Cult of Luna, Isis, Russian Circles, Palms, Deftones, and Pelican have fused metal with post-rock styles. The resulting sound has been termed post-metal.
Post-rock appears to take a heavy influence from late 1960s U.S. group The Velvet Underground and their "dronology" — "a term that loosely describes fifty percent of today's post rock activity". A 2004 article from Stylus Magazine noted that David Bowie's album Low (1977) would have been considered post-rock if released twenty years later.
British group Public Image Ltd (PiL) were also pioneers, described by the NME as "arguably the first post-rock group". Their second album Metal Box (1979) almost completely abandoned traditional rock and roll structures in favor of dense, repetitive dub and krautrock inspired soundscapes and John Lydon's cryptic, stream-of-consciousness lyrics. The year before Metal Box was released, PiL bassist Jah Wobble declared, "rock is obsolete".The Flowers of Romance (1981), their third album, was an even more radical departure, emphasizing rattling percussion and abstract tape music.