William Hayes (born 1954) is an American composer and musician known primarily for his work in the genres of contemporary classical music and jazz. His compositions often blend elements of both genres, showcasing intricate harmonies and rhythms. Notable works include his chamber pieces and orchestral works, which have been performed by various ensembles and orchestras. Hayes's impact on music is seen in his innovative approach to form and structure, as well as his ability to integrate improvisational elements into classical frameworks. He has also contributed to music education, influencing a new generation of musicians and composers. While not as widely recognized as some of his contemporaries, Hayes has carved a niche for himself and is respected within music circles for his unique contributions to the evolving landscape of modern music.