Electronic musical instrument interactively connected with a music application apparatus automatically returns a response signal when a predetermined identification request signal is received from the music application apparatus. Upon receipt of the response signal transmitted by the musical instrument in response to the identification request signal, the application apparatus determines whether or not the connected musical instrument is of a predetermined identity. Thus, for each electronic musical instrument authorized to execute the music application, the application apparatus can perform control to allow the music application to be executed in a normal mode, while, for each electronic musical instrument not authorized to execute the music application, the application apparatus can perform control to inhibit the application from being executed or allow the application to be executed only in a limited function mode.