Duncan won the 2005 BBC Young Composer of the Year competition and was Principal Composer for the National Youth Orchestra of Great Britain. His works have been performed, recorded and broadcast by ensembles such as the London Symphony Orchestra, BBC National Orchestra of Wales, Swedish Radio Symphony, Endymion Ensemble, The Sixteen, the Navarra Quartet, BBC Singers, Sinfonia Viva and Streetwise Opera.
His recent chamber arrangement of a selection of Dvorák songs for Magdalena Kožená received critical acclaim across Europe. Current commissions include an encore for the Bamberger Symphoniker to be premiered conducted by Rafael Payare in March 2019. His latest project, a 30-minute orchestral work Rainbow Beats for the South African organisation MIAGI (Music Is A Great Investment) was premiered on a major tour of Europe in Summer 2018 in celebration of Nelson Mandela's centenary and included performances at the Elbphilharmonie, Concertgebouw, Konzerthaus Berlin and Verbier Festival.
Previous works have included a theatrical version of Michael Rosen’s We’re Going on a Bear Hunt for the National Youth Orchestra premiered at the Southbank Centre’s Imagine Festival; BBC Radio 3 commissions for bassoon and string quartet and a duo for viola d’amore and harpsichord; orchestral pieces for Sinfonia Viva; and a work for the Tempest Flute Trio for their debut album on Gabriel Prokofiev's NonClassical label. Ave Maris Stella for brass, singers and dancers, written in collaboration with choreographer Kerry Nicholls and originally commissioned by the Purbeck Art Weeks Festival, was performed throughout 2011 at the Southbank Centre as part of the Festival of Britain and on a tour of Switzerland. Winner of the Christopher Brooks 2010 Memorial Prize, Duncan was Lancashire Sinfonietta’s Composer in Residence for the 2010/11 season.
Also in demand internationally as a conductor, recent highlights have included engagements with the Orchestre de Paris, Symphonieorchester des Bayerischen Rundfunks, London Symphony Orchestra, Swedish Radio Symphony Orchestra, Bamberger Symphoniker, Deutsche Kammerphilharmonie Bremen and a return to Glyndebourne on Tour conducting Brett Dean’s acclaimed Hamlet.
From 2012-14 he was Conducting Scholar of the Berliner Philharmoniker Orchester-Akademie, to which he was appointed on the recommendation of Sir Simon Rattle, and from 2015-2017, he was Principal Conductor of Sinfonia Viva - one of the UK’s most dynamic and versatile ensembles. He also held the post of Associate Conductor of the National Youth Orchestra of Great Britain.
Conducting plans for the 2018/19 season include debuts with the Frankfurt Radio Symphony, Orchestre National du Capitole de Toulouse, Rotterdam Philharmonic, Munich Chamber Orchestra, Royal Liverpool Philharmonic Orchestra, Orchestre de Chambre de Paris, Münchner Rundfunkorchester and the Royal Philharmonic Orchestra. He will also return to the Orchestre de Paris to make his subscription debut, Scottish Chamber Orchestra, Radio-Symphonieorchester Wien at the Musikverein and conduct a new production of Massenet’s Cendrillon for Glyndebourne on Tour.