Bill Wineburgh adds to the debate about the various Tomy Tuneyville
musical organ toys but unfortunately he is not correct with respect to
the compatibility of the music discs.  The Tuneyville Choo-Choo does
not play the same discs as the Tuneyville Player Piano.  The latter,
being a multiplex instrument, requires fewer tracks and the disc is
therefore smaller in diameter.

The Choo-Choo disc is 3-3/4 inches in diameter whereas the Player Piano
disc has a diameter of 3 inches.

The error may have been made in the original patent applications.  Tomy
may have subsequently realised it would be easier to use a multiplexed
musical arrangement directly onto the internal mechanism rather than
using a standard musical arrangement to duplicate the manual keys and
thence through them onto the flute stoppers.

Nicholas Simons, GB