As the movement builds to a climax, the organ is replaced by a piano echoing the main theme, and the brass section lays down an understated backing. The accompaniment increases in tempo, and the drums come in the cello is replaced by a slide guitar, and for the first time there is some limited embellishment and improvisation around the main theme.

The main theme segues seamlessly into the second movement, which opens with a series of bass and organ arpeggios while a cello reprises the main theme. But as a motorcycle roars off into the distance, discipline, and the main theme, is restored. This feel-good melody is suddenly interrupted by a return of the argumentative brass, and everything else falls silent, to be replaced by intermittent background sound effects: first, a whinnying horse, then several explosions, a rocket taking off, and a train rushing through a tunnel. Finally, the conflict is resolved: there is one last fanfare before the drums and bass join in for the first appearance of the anthemic main theme. Then the brass section comes in with a series of short competing fanfares, rasping trumpets on the one side, blaring trombones on the other. The first movement opens with a long, droning chord on a Hammond organ that grows slowly in intensity.

The way the band, the brass and the choir complement each other throughout the piece marks it out as much the more successful of the two. Unlike similar attempts at the time to fuse rock with more ‘serious’ elements, such as Deep Purple’s Concerto for Group and Orchestra, in which the orchestral contributions almost seemed irrelevant, Atom Heart Mother is a fully integrated suite of six ‘movements’. However, although the tracks on the second side of the album cannot be ranked among the band’s finest work, the title track, which occupies the whole of side one, deserves a better reputation. Pink Floyd were never to attempt anything quite so grandiose again. The album was not well received by the critics at the time, which is a good reason for attempting to escape responsibility for its creation. Lead guitarist David Gilmour, speaking in 2001.

Atom Heart Mother Suite Theme