A method and apparatus for limiting which player pianos can properly play notes within a media file or stream without playing additional "bad notes" encoded in the stream for disrupting the playback of that musical composition so as to prevent playback on unauthorized systems. Bad notes are encoded within a file or stream containing the proper "good notes" of the composition along with control commands to allow identifying the bad notes (e.g., by location, relative position, characteristics and so forth). Player pianos of a first manufacturer, having the proper programming, properly decode the control commands to locate the bad notes and prevent them from being played back with the good notes, therein properly rendering the musical composition. Player pianos from other manufacturers will play all the notes thus obfuscating the playback of the musical composition. Fidelity of playback on authorized system is not affected.