The elusive drone practitioner. Organum runs bowed metal, struck cymbal and massed string through slow superimposition until the result sounds not futuristic but ancient. The brevity is the discipline.
Jackman's route into sound ran through the English experimental tradition rather than through rock. His participation in the Scratch Orchestra, the large and deliberately open ensemble convened by Cornelius Cardew in 1969, placed him among players for whom a graphic instruction or a found action counted as a score; the same milieu produced AMM and the percussionist Phil Dadson. He was an active member from 1969 to 1972, and one of the contributors to Cardew's Scratch Music anthology published by Latimer in 1972. What he took from it, on his own account, was permission: the sense that untrained and tentative ideas could be realised without apology.
The recorded catalogue proper begins at the end of the 1970s. From 1979 Jackman released cassette singles in very small numbers, under his own name or as Monoplane, in step with the underground tape culture of the moment. The Organum name arrives in 1983, and with it the sound the project is known for: no melody and no pulse in the ordinary sense, but a dense, overtone-heavy mass produced by superimposing bowed and struck sounds until the individual sources are no longer separable. Massed string, metal percussion, bowed cymbal, wind and voice are the recurring materials. Jackman has described the making as an almost archaeological accident, the aim being invention to the point of eccentricity, an alarm-clock case scraped round a rusty bicycle rim for twenty minutes, and the result coming out sounding not new at all but like something from the very beginning of music-making.
The tag most often reached for is post-industrial, and Organum did move within that world, sharing labels and personnel with Nurse With Wound and the United Dairies and Touch circles around it. But the description sits awkwardly. There is nothing of the machine-age imagery the term usually carries; the closer references are early and ritual musics, and the drone lineage that runs through Tony Conrad and La Monte Young. Several recordings were made as location-specific events, taking advantage of the sound of tunnels, caves, an overpass and open ground, so that the space itself becomes part of the instrument.
Collaboration is built into the method. Eddie Prévost of AMM, Steven Stapleton, Christoph Heemann, Andrew Chalk, Michael Prime, Robert Hampson, Jim O'Rourke and Z'EV all pass through the catalogue, and Prévost, Stapleton and Heemann each issued Organum records on their own labels, Matchless, United Dairies and Streamline respectively. The relationship with the extreme-reduction acts is characteristically oblique: Organum shares releases with The New Blockaders, and once made a record for The Haters without the involvement of any member of that group. The visual work is not a sideline. Most Organum sleeves carry Jackman's own collage, meticulous and brightly coloured, and the artwork is as much a signature as the sound.
After a long and productive run of vinyl in the 1980s and CDs in the 1990s and 2000s, Jackman reconstituted the project around 2019 as Organum Electronics, and began a sustained late series for Die Stadt that also brought work out under his own name for the first time. The recent records, among them Herbstsonne (2019) and Silence In That Time (2020), move to calmer ground, built from tampura, organ, piano, bells and the sound of crows, but the principle holds: a single sustained field, patiently layered, and kept short.