A music composition system for composing music segments comprises: a computer interface comprising at least one external input for receiving from an external device a request for a musical composition; a controller configured to determine based on a request received at the external input a plurality of musical parts for the musical composition; and a composition engine configured to generate, for each of the determined musical parts, at least one musical segment in digital musical notation format, the musical segments configured to cooperate musically when performed simultaneously. The computer interface comprises at least one external output configured to output a response to the request, the request comprising or indicating each of the musical segments in digital musical notation format for rendering into audio data at the external device.