Abstract: A multi-purpose sound/data system which is capable of recording and reproducing a multitude of disparate and dissimilar information being digital and/or analog in nature in such a way so that there is no interference between the different information channels. This system is principally intended to be applied to motion picture film, but it is equally applicable to television and other devices by which sound, data and pictures may be electrically, mechanically or optically recorded and reproduced. It is an important feature that a film recorded with this system can be reproduced by any standard photographic soundhead without alteration, in the same way as a normal photographic soundtrack. This invention confines itself to the layout of the tracks to present a compatible format and does not deal with the methods of recording and reproduction.