Octophonic sound is a form ofaudio reproduction that presents eight discreteaudio channels using eightspeakers. For playback, the speakers may be positioned in a circle around the listeners or in any other configuration.

Typical speaker configurations are eight spaced on a circle by 45° (oriented with first speaker 0° or at 22.5°), or the vertices of a cube to create a double quadraphonic set-up with elevation.^[1] In reference to his own work,Karlheinz Stockhausen made a distinction between these two forms, reserving the term "octophonic" for a cube configuration, as found in hisOktophonie and the electronic music for scene 2 and the Farewell ofMittwoch aus Licht, and using the expression "eight-channel sound" for the circular arrangement, as used inSirius,Unsichtbare Chöre, or Hours 13 to 21 of theKlang cycle.^[2][3] Whilequadraphonic sound uses four speakers positioned in a square at the four corners of the listening space (either on the ground or raised above the listeners), this cubical kind of octophonicspatialization offers both horizontal and vertical sound spatialization, meaning listeners get a sense of height. In order for such movement in space to be heard, it is necessary thatrhythms be slow, andpitches change mainly in smallsteps or inglissandos.^[4]

Some notable composers who have worked with octophonic spatialisation include Karlheinz Stockhausen,Jonathan Harvey,Gérard Pape, andLarry Austin. The first known octophonic (that is, eight-channel) electronic music wasJohn Cage'sWilliams Mix (1951–53) for eight separate simultaneously played back quarter-inch magnetic tapes.^[5][6] Austin later made a surround-sound octophonic mix ofWilliams Mix,Williams (re)Mix[ed] (1997–2000), using the score and different sound sources.^[7] This version is intended to be played back on eight speakers surrounding the audience in a 360° circle, using (unlike Cage's original version) stereo source recordings heard in adjacent speaker pairs.^[8] Octophonic sound (in the general sense of eight-channel playback) was stimulated primarily by "the equal coverage it provides to all listening angles" and also by the precedence of eight-channel (initially tape) sound and subsequent ease of playback.^[6]

• Height channels

• Austin, Larry. 2004. "John Cage'sWilliams Mix (1951–3): The Restoration and New Realisations of and Variations on the First Octophonic, Surround-Sound Tape Composition". InA Handbook to Twentieth-Century Musical Sketches, edited by Patricia Hall and Friedemann Sallis, 189–213. Cambridge and New York: Cambridge University Press.ISBN 978-0-521-80860-6.
• Collins, Nicholas. 2010.Introduction to Computer Music. Chichester: John Wiley.ISBN 978-0-470-71455-3.
• Leider, Colby. 2004.Digital Audio Workstation. New York: McGraw-Hill.ISBN 978-0-07-142286-4.
• Stockhausen, Karlheinz. 1993. "Octophony: Electronic Music fromTuesday from Light", translated byJerome Kohl.Perspectives of New Music 31, no. 2 (Summer): 150–70.
• Stockhausen, Karlheinz. 2000. "Neue Raum-Musik: OKTOPHONIE". InKomposition und Musikwissenschaft im Dialog I (1997–1998), edited by Imke Misch andChristoph von Blumröder, 60–77. Signale aus Köln: Musik der Zeit 3. Saarbrücken: Pfau-Verlag.ISBN 3-89727-049-8.

• Sound production technology
• Spatial music