Though Les Rallizes Dénudés, also known as Hadaka no Rallizes, were one of the earliest and most revolutionary Japanese psychedelic rock bands, and existed off and on through four decades, they are also one of the most obscure, barely known even in their native country. This cult of noise terrorists shrouded themselves in mystery, seldom touring and releasing no proper studio albums. Their sound presages the later psychedelic experimental noise of Fushitsusha, High Rise, Acid Mothers Temple, and others more than any other Japanese psychedelic group from the late '60s. Most of the recordings bearing the group's name are unofficial bootlegs, but a handful of authorized releases surfaced in 1991, including '77 Live, one of their most well-known works. These were reissued in 2022, along with The Oz Tapes, recorded in 1973.

Revolving around guitarist and vocalist Mizutani Takashi, Les Rallizes Dénudés formed in November 1967 at Kyoto University, inspired by Exploding Plastic Inevitable-era Velvet Underground as well as the over-amplified rock of Blue Cheer. By 1968 they were gigging live and even began a regular collaboration with an avant-garde theater troupe, which ended the next year because of Les Rallizes' penchant for extreme volumes of sound. Not only did they use massive amounts of feedback at loud volumes, their stage shows used strobe lights, mirror balls, and other effects for a live experience that was a total sensory assault.

Les Rallizes also aligned themselves with radical left-wing politics, performing at the front lines of student demonstrations against Vietnam and even the student occupation of Kyoto University in April 1969. One original member, Wakabayashi, was involved in the Japanese Red Army hijacking of a flight to North Korea, known as the Yodo-go incident, and because of Mizutani's own connections with the Red Army, the group's gigs became more infrequent and clandestine. They didn't record much in the studio, and the only music of theirs to come out on vinyl at this time was one side of the double-LP compilation Oz Days Live, released by Oz Discs in 1973. In fact, Les Rallizes kept going throughout the '70s and '80s without releasing a thing, and then suddenly they put out three CDs of archival recordings in 1991, and a video the next year. Of these, the double CD/LP '77 Live highlights them at the top of their form, with 10- to 20-minute tracks of intense guitar feedback and drones over repetitive rhythms and heavily distorted vocals.

Les Rallizes played their final gig in October 1996, nearly 30 years after their inception. All their albums were released in very limited quantities, and numerous bootlegs have surfaced over the years. Because of their reputation for secrecy and violence, as well as the difficulty in tracking down their recordings, Les Rallizes Dénudés have taken on an almost mythic status.

An official Les Rallizes Dénudés website was launched in 2021, revealing that Mizutani had passed away in 2019. The group also announced official remastered editions of their recordings. Several recordings appeared on the Temporal Drift label in 2022, including The Oz Tapes, which included the band's material from Oz Days Live and other previously unreleased music. ~ Rolf Semprebon & Paul Simpson, Rovi