Composer of acoustic and electronic music, most often for live music ensembles and for symphony orchestras, performed in concerts in over fifty countries. He collaborated with Harold Pinter on a radio opera. He has taught in Austria, Germany and Azerbaijan. The Times wrote this: "James Clarke’s String Quartet No.2 was forceful, big-boned and unashamed of the sawmill screech; not a work you’d wish to meet alone in a dark alley." The Arts Desk reported that his music "was thrillingly, almost treasonably, un-British." His electronic work uses and transforms concrete sounds, frequently taken from his own orchestral or instrumental music.