- Synonymous with avant-gardism (Paul Griffiths, Robert Fink and Herbert Eimert)
- Music made in a laboratory (Lejaren Hiller, Pierre Schaeffer)
- The performance of music of which the outcome cannot be foreseen (John Cage, Michael Nyman, Wim Mertens and Joaquim M. Benitez)
- Music in which the innovative component (not in the sense of newness found in any artistic work, but instead substantial innovation as clearly intended by a composer and/or performer) of any given aspect of a given piece or performance takes priority above the more general technical craftsmanship expected of any art work
(Source - Leigh Landy (1991). What's the Matter with Today's Experimental Music? Chur: Harwood Academic Publishers: 3-7.)