Oram's composition machine consisted of a large rectangular metal frame, providing a table-like surface traversed by ten synchronised strips of clear, sprocketed 35mm film.
The musician drew shapes on the film to create a mask, which modulated the light received by photocells.
Although the output from the machine was monophonic, the sounds could be added to multitrack tapes to provide more texture and create polyphony.
[1][2] The Oramics machine, which creates music from graphic elements uses similar principles to the various methods of Graphical sound production appearing in the 1930s, e.g. Yevgeny Sholpo's "Variophone", which produces sound by reading shapes cut into and drawings on cardboard.
In 2016 Tom Richards, a PhD Student at Goldsmiths, University of London, re-imagined and built a working Mini-Oramics machine.