Abstract: A tracker bar for a player piano is made of two pieces which seal together without the use of gaskets. The two pieces are made of plastic and are solvent-fused together. One of the pieces, an interface member, provides for widthwise staggering of pneumatic hose connections for a single row of passages in the other piece, a registry member. The interface member has three rows of tubes and includes channels on its front or paper side to accommodate widthwise offset between the tubes and various of the passages in the registry member, which passages register with holes in the player piano paper tape.

Abstract: This apparatus pertains to mechanical and electromagnetic apparatus for controlling player piano operation. The conventional player piano paper tape which opens and closes pneumatic holes in a tracker bar is replaced by a valve board and a plurality of electromagnetic valves. Each electromagnetic valve operates to control air passage through one of the holes in the tracker bar.