A system for playing a selected one of multiple audio tracks recorded in synchronized fashion with a motion picture on an optical disk. The optical disk has encoded on it a mixing master music and effects ("M&E") track, or a switching master M&E track. Individual audio tracks are provided for language-specific versions of the same motion picture, but these tracks have data recorded in them only where there is dialog. In this way, for many a motion picture, all tracks but masters will have data recorded for well less than half of the running time of the motion picture. When a mixing master is used, it is mixed with a language-specific track when the latter has dialog; the mixing master contains no dialog. If a switching master is used, it may contain dialog recorded with the M&E; when a language-specific track has dialog recorded in it, it also contains M&E and the track is played to the exclusion of the switching master.