Born in Leeds, Yorkshire in 1950, Duncan was educated at Burton on Trent Grammar School, during which time he also studied organ with Richard Greening MA,BMus,FRCO at Lichfield Cathedral. In 1968 he entered the Birmingham School of Music (now the Royal Birmingham Conservatoire) continuing his organ studies with George Miles. In 1970, Duncan gained the diplomas of ABSM (General Musicianship) and ABSM (Organ) and one year later, graduated GBSM. In 1972 he was awarded the Certificate in Education from the University of Reading. He has taught in schools in Wiltshire and Hampshire since 1973 and in 1979 was appointed to the staff of the Gregg School, Southampton where he was Director of Music for over thirty three years before retiring in 2012. Apart from Church Music, he has a particular interest in plainsong and (to show the spectrum of his taste) an interest in military music. In 2006, he was elected a Fellow of the Academy of Saint Cecilia. In 2013, after a three year course in theology, Duncan was licensed as a Lay Minister in the Diocese of Winchester and serves at St Michael the Archangel Church Southampton, (since 2018) having been LLM and Organist and Director of Music at St Mary's Church, Southampton City Centre. In December 2015, Duncan relinquished the position as Director of Music in order to concentrate on ministry in what was the Southampton City Centre Parish. Since 2018, as well as being at St. Michael's Duncan also works as Padre to 424 (City of Southampton) Squadron, RAF Air Cadets.