Oliver-John began his musical career as a chorister at Westminster Abbey. He graduated in 2006 with a first class honours in Music from the University of Manchester. He has been Music Director of Hampstead Garden Opera Company since 2008. He has recently completed a year as keyboards apprentice to the Monteverdi Choir under Sir John Eliot Gardiner and has performed at the Proms and across Europe as a member of the English Baroque Soloists. He has previously held positions as cover conductor to the Royal Ballet and Acting Director of the Halle Youth Choir. Oliver-John is in demand as a continuo player, and is harpsichordist and co-director for Musica Poetica London. He is also busy as a freelance tenor, regularly singing for Philharmonia Voices and as a tenor deputy for Stile Antico.