Graphical user interface [GUI] specifically adapted for electrophonic musical instruments, e.g. interactive musical displays, musical instrument icons or menus; Details of user interactions therewith for graphical creation, edition or control of musical data or parameters using icons, e.g. selecting, moving or linking icons, on-screen symbols, screen regions or segments representing musical elements or parameters for graphical orchestra or soundstage control, e.g. on-screen selection or positioning of instruments in a virtual orchestra, using movable or selectable musical instrument icons