The BTRON computer architecture, developed as part of the Japanese TRON (The Real-Time Operating Nucleus) project, contains specifications for several buses. The application of one of these, the mu BTRON bus, as a music local area network, is discussed. Simulation results for mu BTRON bus performance when electronic musical instruments are connected to BTRON-based computers are reported. Electronic musical instruments were chosen for the simulation target because they need real-time performance, a feature of the mu BTRON bus.