There is disclosed a playback and recording assemblage for a sound slide projector. This assemblage includes sound slides which are coated on opposite sides of a widened frame portion with magnetic layers. These layers serve to record thereon sound tracks in spaced apart parallel relationship. Recording or playback of such sound tracks is effected by one or more pairs of sound heads which are alternately moved into and out of contact with the two layers so that one head of a pair coacts with one layer and the other head of the pair coacts with the other layer, and so forth, until all sound tracks on both layers are alternately but in sequence recorded or played back, thereby completing a message on the two sides of the sound slide. Upon completion of the message the sound heads are returned to their respective starting positions whereupon recording or playback of a message on another slide may be started.