Mnemonists, on the first album called Mnemonist Orchestra, is U.S collective of avant-garde musicians from Colorado, led by Mark Derbyshire and William Sharp. Their music is a mixture of modern classical, experimental sounds, noise, industrial, avant-garde and free jazz. Their releases were published by their own self-produced label Dys between 1981 and 1986.

By 1985 the group had split off into separate groups for visual and audio work. From that time, Mnemonists operated only as a visual arts collective while the musical activity was taken over by a new group called Biota that featured a few of the musicians involved with Mnemonists as well as many new members. The two groups co-exist and share only a few members. The Mnemonist Orchestra album was recorded in March 1979 at Fort Collins, Colorado. The musicians improvised within loose arrangements intended to suggest the concept of each piece. All pre-taped sounds were mixed live with the other instruments.