As a student John was Assistant Conductor of Schola Cantorum Oxford, Conductor of the Kodály Choir, occasional organist and conductor of the BBC Singers’ Radio 4 morning live morning service; he worked as a freelance rehearsal accompanist under Martindale Sidwell, John Eliot Gardiner, Ian Humphris, John Poole and Barry Rose; he accompanied and conducted the choir of St Paul’s Cathedral for services and recordings, featuring on three LPs, two as organist and one as producer.

He was awarded Fellow of the Royal College of Organists, Associate of the Royal College of Music and Licenciate of the Royal Academy of Music. He held the position of Organist and Master of the Choristers in St Patrick’s Cathedral Dublin from 1977 to 2001. He has recorded for Guild Records, Pinewood Records, Polygram and BBC Radio 3; he has conducted the Guinness Choir, Third Day Chorale, RTE Chamber Choir, RTE Concert Orchestra, Orchestra of St. Cecilia, Hibernian Orchestra, the RTE National Symphony Orchestra in part of a concert in the Point Theatre featuring St Patrick’s Cathedral Choir with Plácido Domingo, and the Irish Chamber Orchestra in various concerts including Sir Peter Pears’ seventieth birthday concert (1980) in which Pears sang Britten’s Nocturne. He has also conducted BBC Songs of Praise twice, BBC Radio 3 Choral Evensong more than 15 times, as well as conducting music for films, advertisements, documentaries and concerts.

As well as conducting the Goethe-Institut Choir John is currently Music Teacher at St Patrick’s Cathedral Grammar School, Chorus Master of the Dublin County Choir and the Founder and Conductor of John Dexter Harmony. As a composer, most of his work has been in the area of arranging and adapting music for St Patrick’s Cathedral, for JDH and for his family ensemble. The Goethe Institut Choir commissioned a new work Hilariter from him for its 40th Anniversary Concert in the National Concert Hall in December 2005. John Dexter lives with his wife Alison and their seven children in Ballinteer, Dublin.