Formed in 1965 by three players from the emerging British jazz avant-garde - Keith Rowe and Lou Gare had played with the great progressive big band leader Mike Westbrook and Eddie Prévost played in a post-bop group with Gare - AMM quickly evolved from a free jazz group into something decidedly more difficult to categorise. By the time these recordings were made, two more members had joined the group: another Westbrook associate, Lawrence Sheaf, and the radical composer Cornelius Cardew. Then at work on his masterpiece of graphic notation Treatise, Cardew brought with him extensive experience of the post-serialist and Cageian currents in contemporary composition. Using a combination of conventional instruments and unconventional methods of sound production (most famously Keith Rowe's prepared tabletop guitar, but also prepared piano and transistor radio), the group performed improvised pieces often running for over two hours and ranging from extended periods of silence to terrifying cacophonies.
Evan Parker famously described the improvisational logic of AMM's music as 'laminal', in contrast to the 'atomistic' approach more common among the generation of British improvisers (Bailey, Rutherford, Stevens and co.) to which he himself belonged. AMM improvised in layers: layers of sound subtly rising and falling or abruptly starting and stopping without being propelled by the implied pulse of free jazz improvisation. Rather than a pulse, AMM's music began with the sound of the room in which it was played, the Cageian anarchy of silence. By embracing the non-synchronous simultaneity of layered sound, AMM was able to create a musical container into which nearly anything could be incorporated at any moment: on AMMMusic, long tones sit next to abrasive thuds, the howl of uncontrolled feedback accompanies Cardew's purposeful piano chords, radios beam in snatches of orchestral music (and, on the LP's second side, an extended fragment of 'Mockingbird').
AMM's clearest break with jazz-based improvisation concerned the idea of individuality. Where improvised music has tended to foster the development of idiosyncratic stylists who move freely from one group to another, AMM, initially through an engagement with eastern philosophy and mysticism and later though a politicized communitarianism, sought to develop a collective sonic identity in which individual contributions could barely be discerned. In the performances captured on AMMMusic
the use of numerous auxiliary instruments and devices, including radios played by three members of the group, contribute to the sensation that the music is composed as a single monolithic object with multiple facets, rather than as an interaction between five distinct voices.
- Francis Plagne