John Fonville is a flutist and composer. Fonville specializes in extended techniques on the flute, especially microtonality, and performs on instruments including a complete set of quarter tone (Kingma system) flutes. He has premiered works by composers including Ben Johnston, Salvatore Martirano, Joji Yuasa, Roger Reynolds, Hiroyuki Itoh, and Paul Koonce.
He is a member of the Tone Road Ramblers, the Eolus Quintet, and the UCSD Department of Music's Performance Lab. Fonville is the author of Microtonal Fingerings for Flute (1987), A Pedagogical Approach to the Flute Etudes of Joachim Andersen (1981), and "Ben Johnston's Extended Just Intonation: A Guide for Interpreters" (1991).