Hi Robbie,  These guys are several years behind.  I have a plastic
toy train with many pieces of plastic track which have sliding
adjustable "bumps" on bars across the track.  The engine plays a tune
with whistles that are engaged when a bump on the track is run over.
It allows for any number of songs to be programmed by sliding the
"bumps" to the correct position.

It has two problems, which may be the reason that I have the only one
I ever saw: (1) it takes a _great deal_ of patience to program a fairly
long song, and (2) the blower to play the whistles is quite loud and
distracts from the tune.

Unfortunately, I am enjoying the warm sunny weather in Florida and
the train is hiding inside my Michigan house which they tell me is
surrounded by several feet of snow.  When I return (maybe the snow
will be gone by 4th of July) I will send more information on my train.

I applaud the idea behind this experimental toy you wrote about.
I have several toys of various vintages that allow a child (or a big
kid like me) to program their own music.  This has been an idea that
has been around for at least 65 years, using music box movements and
punched paper, metal strips with screw in pins, tabs on a bar that
lifts a xylophone hammer, and whistles with self punched paper, etc.

On a completely unrelated subject, Mattel's Barbie Doll turns 55
years old this month.  I doubt that many of you knew that Mattel was
making musical toys 10 years earlier, in 1949, with various metal
nursery rhyme toys that played "rubber band" movements with songs like
"Black Birds in a Pie" and "Farmer in the Dell" and several others.

Keep up the good work, guys.  I really enjoy my daily MMD!

Beatrice Farmer