Blankette projector

In a music projector, the combination of a case having a transluscent screen on its front side, and a mechanism inside said case for projecting a music sheet page image upon a rear side of said screen for being viewed from a front side of said screen, said mechanism including a lens, a first electric lamp with a reflector, a space between said lens and lamp into which a plurality of film cassettes are slidable for selected alignment therebetween, each cassette containing a film strip wound at its opposite ends upon a pair of reels so to expose a portion therebetween for alignment with said lens and lamp, said film having a plurality of music sheet pages photographed thereupon, wherein said cassettes are slidably supported upon a pair of transverse rods supported in side walls of said case, said cassettes being detachably attached to a band so to slide together, and a tooth on each cassette together forming a toothed rack, said rack being engaged by a first gear on a shaft of a rotatable control knob at a front of said case, wherein a second gear on said control knob shaft engages a toothed rack of a transluscent plate having a sequence of different numerals imprinted thereupon and movable behind a window opening in said case front wall, and a second lamp inside said case being behind said plate and aligned with said window opening.