A member of the Association for the Advancement of Creative Musicians (AACM) since 1971, Lewis's work in electronic and computer music, computer-based multimedia installations, and notated and improvisative forms is documented on more than 150 recordings. His work has been presented by the BBC Scottish Symphony Orchestra, London Philharmonia Orchestra, Radio-Sinfonieorchester Stuttgart, Musikfabrik, Mivos Quartet, London Sinfonietta, Spektral Quartet, Talea Ensemble, Ensemble Pamplemousse, Wet Ink, and others. His opera Afterword (2015) has been performed in the United States, United Kingdom, and the Czech Republic.