David Simon is an organ recitalist, liturgical musician, and music instructor. He is the Director of Music at the historic Church of St. Mary Magdalene in Toronto where he directs the Gallery Choir, accompanies the liturgy, and maintains the musical tradition made famous by the work of his predecessor Healey Willan. David also has the privilege of teaching organ, piano, and music theory at St. Michael's Choir School, having grown up there as a chorister himself. He holds a Doctor of Musical Arts degree from Yale University and has studied with Thomas Murray, Jeff Brillhart, and Patricia Wright. He is a Fellow of the RCCO, winning prizes for top national achievement.

A prize-winning recitalist and improviser, David won first prize in both the Royal Canadian College of Organists (RCCO) national competition and the University of Michigan's organ improvisation competition. David has performed across North America, the UK, Europe, and Russia, and he maintains a busy concert and teaching schedule. He is in particular demand as an organ improvisation teacher, giving lectures for Organ Festival Canada, instructing at the RCCO Summer Organ Academy, and giving masterclasses for various centers of the RCCO; David also maintains a private studio which includes students from across Canada.