Tortoise

Defining Tortoise wouldn't really make sense in itself. To say that they came from Chicago (Slint's country, too) towards the end of the 1980s would already be a beginning of explanation. They are partly said to be initiators of the Post-Rock style. They are also called progressive. They are easily categorized as Rock, Jazz, Electro, Post-Rock, Indie Rock...
Tortoise is a little bit of it at once; When McCombs and Herndon start the band, they want to make it a rhythmic section free of all the carcans. Although Tortoise has never met this definition, their albums all meet this requirement of improvisation and freedom claimed. The first album, eponymous, released in 1993 is entirely instrumental and makes its instruments its peculiarity: two basses and 3 percussionists (battery, marimbas, vibraphone).
Mentioning Slint, higher, was no coincidence. David Pajo is Tortoise's first 6 string player (Millions Now Living Never Die, 1996). And, by chance, it's this album that gives the long-awaited blow of fame. When Pajo left the band in 1998, Tortoise took a more Jazz path with TNT and Electro with Standards in 2001 and Beacons Of Ancestorship in 2009. Always looking for a gender transcendence.
Tortoise is also the happy participant of some collaborations, notably with Stereolab and Bonnie 'Prince' Billy, among others.