Jonathan began his musical training as a chorister in the choir of Southwark Cathedral, under the direction of Peter Wright. As a treble he later performed as a soloist with orchestras at the Barbican, Queen Elizabeth, and Royal Albert Halls. He also took the roles of First Boy in Mozart’s The Magic Flute for the ENO, and Miles in Britten’s The Turn of the Screw, for which he received high critical praise ("Darbourne’s Miles stands in the line of greats"– The Independent).
After reading Music and singing as a choral scholar at Magdalen College, Oxford, under the direction of Bill Ives, Jonathan went on to further vocal study at the Schola Cantorum, Basel and the Barock Vokal programme in Mainz.
In 2020, Jonathan co-founded The Vache Baroque Festival ('Newcomer of the Year' - Opera Now) for which he has lead three operas and other multi-artform programmes from the harpsichord. In 2022 he was assistant conductor and continuo player for The Grange Festival's production of Handel's Tamerlano, and in 2023 was selected for an ensemble directing masterclass residency with William Christie and members of Les Arts Florissants.
Jonathan directs his own group – Nature’s Voice –, a vocal ensemble dedicated to performing music on themes concerning nature and the environment. Their primary venture launched with a performance at The Temple Church, London programmed on forests and trees, and featured a 360-degree soundscape developed in collaboration with sound producer Dan Samsa.
Jonathan sings with leading European ensembles such as the Dunedin Consort, Concerto Copenhagen, Freiburger Barockorchester, and The Marian Consort. In 2012 he took part in the world premiere of Stockhausen’s opera Mittwoch aus Licht with Ex Cathedra (dir. Graham Vick), which was performed the next year at the BBC Proms. As a soloist, his performance as The Waiter in Steven Oliver's The Waiter's Revenge was reviewed by The Independent on Sunday as "outstanding", with Opera Now writing "Darbourne's lugubrious performance stood out." With his trio Les Etrangers (keyboards and viol), he gives recitals of 17th- and 18th-century music, most recently at the Festival d’Orgue de Masevaux and the Festival de Redon in France.
In demand as an arranger, Jonathan’s commissions have been broadcast live on BBC Radio 3, and have been performed at London venues including the Cadogan Hall and St John’s, Smith Square, as well as internationally. He also runs a male-voice a cappella group, The Oxford Clerks, performing original arrangements from all styles of popular music.