Critic Eduardo Rivadavia describes them as "perhaps the ultimate stoner rock band"[3] and notes they exerted a strong influence on metal in the 1990s.

The band reformed in 2009 and have played sporadic live dates internationally since, with Neurosis drummer Jason Roeder replacing original member Chris Hakius.

[4] Sleep evolved in the early 1990s from the band Asbestosdeath, which was established by vocalist/bassist Al Cisneros, drummer Chris Hakius, and guitarist Tom Choi.

Asbestosdeath expanded to a quartet with the introduction of Matt Pike on guitar, and recorded two singles - "Dejection" for Profane Existence and the self-released "Unclean".

Frequently compared to bands like Saint Vitus, Sleep soon gained a devoted fanbase within the developing doom metal scene.

Recorded at Razors Edge studios in San Francisco, with Billy Anderson as engineer, the tape showcased Sleep's love of all things retro, from the blatant Black Sabbath/Blue Cheer influences, to their fixation with 1970's-style tube amplification.

The label had it remixed and cut up into sections by David Sardy, which led to a deadlock due to the band being unhappy with the result.

In May 2009, Sleep reformed to perform two exclusive reunion sets in Britain as part of the All Tomorrow's Parties music festival.

During these shows, the band performed an unheard song that had been written during the Dopesmoker recording sessions, titled "Antarcticans Thawed," for the first time.

[12] In November 2017 the band members posted a message in Morse code stating that they had almost finished recording material for a new album.

[21] Musically, Sleep's sound has been characterized as stoner rock built upon slow, down-tuned bass playing alongside similarly low guitar riffs.

"[23] Al Cisneros stated that smoking cannabis was vital to the song's creative process: "I was really dependent on the space I got into when I was using it [...] The line, 'Drop out of life [with bong in hand],' was kind of a creed at that point.

[26] Current lineup Former members Timeline Note: The band's album Dopesmoker (2003) was originally released as Jerusalem in 1999 by The Music Cartel.