William is Director of Music at St Barnabas's Church, Dulwich and Organ Curator of London’s Royal Festival Hall (RFH), where he has revived both the RFH organ and the Organ Recital Series.

He read music at the University of Durham and was organ scholar at the College of St Hild and St Bede, later becoming Caedmon Fellow and Director of Music whilst studying for his doctorate. William studied organ with Ian Shaw, David Hill, David Sanger, James O’Donnell and with Daniel Roth in Paris on a scholarship.

William enjoyed a successful ten-year duo-partnership with the organist Jeremy Barham, performing extensively throughout the United Kingdom and Europe. Recent concert highlights have included solo appearances in the Canary Islands in Janácek’s Glagolitic Mass, Saint-Saëns's Third Symphony, Poulenc’s Organ Concerto with the Royal Philharmonic Orchestra under Carl Davis. He has given recitals with the violinist Levon Chilingirian – most recently at the Esplanade in Singapore, where he ran a week-long education programme with composer Duncan Chapman. An experienced conductor, William has directed eleven stage productions, including Britten’s children’s opera Noye's Fludde, as part of the Millennium Awards for All. Concerts in 2007 included performances of the Duruflé Requiem, Britten’s Cantata St Nicholas, recitals for the Sevenoaks and Dulwich Festivals and a concert at Saloman’s Theatre on the restored Welte organ.

Broadcast work has included BBCTV, as well as independent radio and television both in the UK and abroad, and presenting Building a Library and Record Review on BBC Radio 3. Recordings include ten discs of choral music and top-selling Great Organ Classics for Classic FM and BMG/Conifer. William has published for Boosey & Hawkes, edited two BIOS journals, co-written four books in the series Targeting Music for Schott & Co. and regularly contributes articles and features to a wide range of journals and magazines.

In recent years the main focus of his work has moved to independent organ consultancy. Current projects include the Royal Festival Hall, Christ’s Chapel Dulwich, St Michael Cornhill, Christ Church Spitalfields, Manchester Town Hall, St Mary Redcliffe, The Lord Mayor’s Chapel Bristol, the Honourable Society of Lincoln’s Inn and Radley College. He is Organs Adviser to the Diocese of Southwark, Chairman of the Association of Independent Organ Advisers, and a member of the Council for the Care of Churches Organs Committee.

William teaches Organology at the Royal Academy of Music; the course focuses on the national schools of organ construction and repertoire, and how consideration of them affects the approach to performance.