His creative output consists of orchestral, chamber, solo, electroacoustic, and vocal music.
Harley studied at Western Washington University (B.Mus., magna cum laude, 1977–1982), Royal Academy of Music (1983–1985), Université de Paris (1986–1987), Fryderyk Chopin Academy of Music, Warsaw (1987–1988), and McGill University (D.Mus., 1988–1994).
In 2004, he took up a tenure-track position in music at University of Guelph, where he is associate professor.
He is also a member of the American Composers Forum, the Canadian Electroacoustic Community, and the International Computer Music Association.
Arraymusic, Codes d'Accès, Composers' Orchestra,[3] Continuum, Corey Hamm [4] Marc Couroux, ECM, Hammerhead Consort, Kappa, Kore,[5] Kovalis Duo, Duo Vira, Groundswell, Hammerhead Consort, Lafayette String Quartet, McGill Contemporary Music Ensemble,[6] McGill Symphony Orchestra, Elizabeth McNutt, New Music Concerts, Patricia O'Callahan, Oshawa-Durham Symphony, Open Ears Festival, Penderecki String Quartet, Polish Society for New Music, Brigitte Poulin, Prince George Symphony, Ben Reimer, SMCQ,[7] Transmission,[8] Trio Phoenix, Trio Fibonacci, Alain Trudel, University of Guelph Women's Chamber Choir, Vancouver Bach Choir, Ellen Waterman.