These include working in contemporary music with orchestras such as London Sinfonietta; accompanying silent films with Harmonie Band; regular engagements as Musical Director at the National Theatre, and numerous recording sessions for Film and TV. He has broadcast new solo piano works on BBC Radio 3.
Walter has worked with The Michael Nyman Band, The Hilliard Ensemble and the cutting-edge ensemble Icebreaker in Italy, Poland, Czech Republic, Germany and Holland.