Short for "light synthesiser", a term which I began using in the mid-80s to designate a device or piece of software intended to produce a dynamic abstract graphical display to accompany music. Some call such devices audiovisualizers. Lightsynths can be entirely user-operated, or driven by realtime analysis of the audio stream, or a combination of both. My own efforts in this field consist of Psychedelia, produced for the Vic-20, Commodore 64, Spectrum and MSX computers; Colourspace, produced for the 8-bit Atari, Atari ST and BBC Micro computers; Trip-A-Tron, for the Atari ST and Commodore Amiga computers; and the VLM sequence, which was implemented on a custom Transputer rig, the Atari Jaguar videogame system, and the Nuon DVD platform.