Tenney was born in Silver City, New Mexico, and grew up in Arizona and Colorado. He attended the University of Denver, the Juilliard School of Music, Bennington College (B.A., 1958) and the University of Illinois (M.A., 1961). He studied piano with Eduard Steuermann and composition with Chou Wen-chung, Lionel Nowak, Paul Boepple, Henry Brant, Carl Ruggles, Kenneth Gaburo, Lejaren Hiller, John Cage, Harry Partch, and Edgard Varèse. He also studied information theory under Lejaren Hiller, and composed stochastic early computer music before turning almost completely to writing for instruments with the occasional tape delay, often using just intonation and alternative tunings. Tenney's notable students include John Luther Adams, John Bischoff, Peter Garland, Larry Polansky, Charlemagne Palestine, and Marc Sabat. See: List of music students by teacher: T to Z#James Tenney. He performed with John Cage, as well as with the ensembles of Harry Partch (in a production of Partch's The
He lived in New York during much of the 60s, where a large part of his contribution to the music scene was funnelled through «Tone Roads», a group founded with Malcolm Goldstein and Philip Corner, and for which his partner Carolee Schneemann designed beautiful flyers and programs. He was exceptionally dedicated to his great New England forebear Charles Ives, many of whose compositions he conducted (including the first performance of «in re, con moto»); his interpretation of the «Concord» Sonata for piano was much praised.
Tenney's work deals with perception (For Ann (rising), see Shepard tone), just intonation (Clang, see gestalt), stochastic elements (Music for Player Piano), information theory (Ergodos, see ergodic theory), and with what he called 'swell' (Koan: Having Never Written A Note For Percussion for John Bergamo), which is basically arch form.