The nature of re-recording as it applies to motion picture production is described in some detail by showing what happens to a typical picture in the re-recording department after shooting on the set has been completed and the picture has been edited to the satisfaction of the producer. — Sound is added to those portions of the picture that have been photographed silent because of the difficulty or impossibility of recording the corresponding sound at that time, as for example, credit titles, montages, miniatures, stock shots, and scenes photographed silent to playbacks of pre-recorded sound. Music that has been especially scored and recorded for the picture together with appropriate sound-effects is added to heighten its dramatic presentation. — Improvements in dialog quality are made if required by employing electrical equalizers, although distortion is often purposely introduced where telephone, dictaphone, radio, and similar types of quality must be simulated as required by the picture. — Proper balance of the relative volume of the dialog and accompanying music and sound-effects is determined to the satisfaction of the re-recording supervisor. All the sounds from as many as a dozen or more different sources are re-recorded to a single composite sound-track which is afterward printed with the picture to make up the final print to be projected in the theater. — The organization of the re-recording department is discussed and the duties of various members of the personnel are outlined. Crews are so made up that an average of from three to six pictures are in work at the same time.