James studied cello with Sue Lowe. He has had masterclasses with Alexander Baillie, Louise Hopkins, Pierre Doumenge, and Anna Shuttleworth.

In 2017 he premiered chamber operas The Jewel Merchants by Rose M. Hall and David Gilbert (Bethlem Gallery, 2017) and hEARd by Theo Jamieson and Lila Palmer (Roman River Music, Mercury Theatre Colchester, 2017), plus folk/children’s opera The Magic Paintbrush by Helen Madden (Barnsley Civic & The Dearne Playhouse, February 2017). In May 2017 he collaborated with Neil Luck on Vexations (Post-Paradise Series, Birmingham, & The Hepworth, Wakefield).

An enthusiastic improviser, James also plays clarinet, piano and otamatone. While in York he played with improvisation collectives BottleGreen (2009-2011) and ish (2017-). In 2015 he performed a set of improvised music based on a collection of African rhythms with percussionist Beau Stocker at York Spring Festival.

He was a member of experimental group The Assembled, led by Dr Catherine Laws, from 2012-16. James and Laws perform experimental work in some kind of duo.

With The Chimera Ensemble (2008–16), he premiered many works by student contemporaries — including Manos Panayiotakis and Paul Edis — and performed music by Birtwistle, Boulez, Liza Lim, Xenakis, Kaija Saariaho, Ada Gentile, Arvo Pärt, Garrett Sholdice, György Kurtág, Desmond Clarke, and Thomas Adès. In 2014 he played one of two solo cello parts in a performance of Morton Subotnick’s Ascent into Air.

James also played with and took a turn leading York Cello Ensemble (2009-12), for whom he arranged pop songs and film music.

As a session musician, he has featured as a soloist on several albums:
Lynette Quek RAFT (2016)
Dave Keegan Dave Keegan (2017)
Sam Forrest Population 4000 (2013)
Burial in the Sky Burial in the Sky (2012)
James Harker The Red Room (2011)
Tryst Tryst Demo 2010 (2010)
Ten Journeys (2009)

Away from instruments, James loves Barbershop music and making sounds with his voice.

As a teenager he formed an a cappella Barbershop group, Something for the Weekend. During his undergraduate he formed Seventh Heaven, a Barbershop Quartet (2008–11). With fellow member Karl Kramer (a’Nish), in 2010 he founded BarberSoc – a Society for the Promotion and Enjoyment of Barbershop Singing for Students in York (…a mixed voice a cappella choir).