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). Away from singing, he became principal viola player in the London Schools’ Symphony Orchestra, playing regularly at the Barbican Hall and touring internationally.

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, the Barock Vokal programme in Mainz with Andreas Scholl, and privately in Molise, Italy. With his trio Les Etrangers (harpsichord/organ and viola da gamba), 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 2020, Jonathan co-founded The Vache Baroque Festival, for which he has lead two operas and two multi-artform programmes of Bach cantatas from the harpsichord, as well as designing sound installations for the grounds. In 2022 he looks forward to working as assistant conductor and continuo player for The Grange Festival's production of Handel's Tamerlano. 


Working regularly as a chorus and choral director for projects with the National Symphony Orchestra, the Locrian Ensemble of London, and the Arb Ensemble, in 2019 Jonathan formed his own group – Nature’s Voice – a vocal ensemble dedicated to performing music on themes concerning nature and the environment. Their primary venture – Sound of Nature – 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, The Marian Consort, and Polyphony. 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."


In demand as a composer and 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 in the USA and at the National Concert Hall, Taipei. He also runs a male-voice a cappella group, The Oxford Clerks, performing original arrangements from all styles of popular music.