* Remastered repress. Comes with printed inner sleeve. * Two records in one, hinged at the exact moment a rock band decided to dismantle itself in the studio and see what was left. Unrest was the second album by Henry Cow, recorded at Virgin's Manor studios across February and March 1974 and released that May. It was the first to feature Lindsay Cooper, whose bassoon, oboe and recorder replaced the saxophone of the departed Geoff Leigh, completing the line-up of Fred Frith, Tim Hodgkinson, John Greaves and Chris Cutler that would carry the group through its most uncompromising years. They were a band of Cambridge intellectuals and conservatory-trained players who treated rock as raw material rather than received form, aligned with the politics and the rigour that would later coalesce into Rock In Opposition, and they made Unrest at the point where their ambitions outran any genre prepared to hold them.

The record splits cleanly down the middle, and the split is the argument. The first side is composed music, taut and written-through, holding some of the group's best-loved pieces - the lurching attack of Bittern Storm Over Ulm, the suspended melancholy of Half Asleep; Half Awake, and Frith's twelve-minute Ruins, a bleak, intricately arranged structure that remains the album's centre of gravity. Parts of it were tracked by a young Mike Oldfield, then in the orbit of the same studio. The mix is more live than its predecessor, the drums pushed forward, the chamber instruments given air to cut through.

Then the floor drops away. The second side was built entirely in the studio, with the band working in loops, varispeed tape and electronics, superimposing improvisation onto composed passages until the line between the two disappears. Bassoon, alto, voice and drums were run at half and double speed; pieces like Linguaphonie and Upon Entering the Hotel Adlon assemble themselves from fragments that seem to arrive from several rooms at once. It is some of the most genuinely strange music a rock label put out in 1974, and it still resists being filed.

Dedicated to Robert Wyatt and Uli Trepte, Unrest sits at the foundation of European avant-rock, the record where Henry Cow proved that composition and free improvisation could occupy the same body without either softening. Reissued by ReR Vinyl, carefully remastered with a printed inner sleeve, faithful to the Virgin original. Classic, historic, and still difficult in all the ways that matter.