In the 1980s the terms indie rock and alternative rock were used interchangeably. By the mid-1990s, as elements of the movement began to attract mainstream interest, particularly grunge and then Britpop, post-grunge and pop-punk, the term alternative began to lose its meaning. Those bands following the less commercial contours of the scene were increasingly referred to by the label indie. They characteristically attempted to retain control of their careers by releasing albums on their own or small independent labels, while relying on touring, word-of-mouth, and airplay on independent or college radio stations for promotion. Linked by an ethos more than a musical approach, the indie rock movement encompassed a wide range of styles, from hard-edged, grunge-influenced bands like The Cranberries andSuperchunk, through do-it-yourself experimental bands like Pavement, to punk-folk singers such as Ani DiFranco. It has been noted that indie rock has a relatively high proportion of female artists compared with preceding rock genres, a tendency exemplified by the development of feminist-informed Riot Grrrl music. Many countries have developed an extensive local indie scene, flourishing with bands with enough popularity to survive inside the respective country, but virtually unknown outside them.
By the end of the 1990s many recognisable sub-genres, most with their origins in the late '80s alternative movement, were included under the umbrella of indie. Lo-fi eschewed polished recording techniques for a D.I.Y. ethos and was spearheaded by Beck, Sebadoh and Pavement. The work of Talk Talk and Slint helped inspire both post rock, an experimental style influenced by jazz and electronic music, pioneered by Bark Psychosis and taken up by acts such as Tortoise, Stereolab, andLaika, as well as leading to more dense and complex, guitar-based math rock, developed by acts like Polvo and Chavez. Space rock looked back to progressive roots, with drone heavy and minimalist acts like Spaceman 3, the two bands created out of its split, Spectrum and Spiritualized, and later groups including Flying Saucer Attack, Godspeed You Black Emperor! and Quickspace. In contrast, Sadcore emphasised pain and suffering through melodic use of acoustic and electronic instrumentation in the music of bands likeAmerican Music Club and Red House Painters, while the revival of Baroque pop reacted against lo-fi and experimental music by placing an emphasis on melody and classical instrumentation, with artists like Arcade Fire, Belle and Sebastian and Rufus Wainright.