When a bedraggled sextet of Japanese acid-rock hippies took to the Whelans stage and announced themselves in a heavily accented, broken-English chant, the crowd's reaction was evenly divided between bemusement and shock - both justified responses in light of the performance to come.

Self-styled as a freak-out group for the 21st century, the band are on a mission to recreate the freeform, 20-minute-jam sensibilities of the more esoteric 1970s rock bands, except to an extreme that would confuse Timothy Leary. Think of Syd Barrett's Pink Floyd doing covers of Captain Beefheart instrumentals.

Looking as if he hasn't come down since Woodstock, the group's guru-like leader, Kawabata Makoto, was the focal point of the performance, although the dynamics of the protracted songs were driven by the band's excellent drummer, whose tightness was all that kept the jams in check and prevented the set from descending into pure noise. The music was so left of centre that much of the audience merely endured the set, even if others were hooked.

Modern pop has compressed the attention span of the average fan to no more than three-and-a-half minutes, something that Acid Mothers Temple's music shows contempt for. Their hour-plus set comprised only four songs, followed, after a cheeky 20-second encore, by a second, 15-minute one.

After such an aural assault, it was impossible to distinguish any musical details; all that remained was an impression of a band who have no interest in contemporary music, who like it loud and whose wanton ignorance of refined music was a confusing, noisy breath of fresh air.