Mike Biel wrote:

Actually they are called Puzzle Records, not Roulette, and they date
> back as far as the 1890s with an example on Berliner Records.
>

I agree that "puzzle record" or "puzzle plate" is the usual term for these
discs, but it may not always be appropriate.  The earliest example I've
seen also happens to be the earliest known experimental gramophone disc of
any kind, dated June 21, 1887, with three tracks.  But there's no
indication that these were meant to be a "puzzle"; presumably the idea was
simply to take full advantage of the space for multiple experiments,
although I suppose if the listener could tell which of the three was being
played back, that would have been a good proof that the recording method
was working.   And then there are the "Double Track" discs on Clarion,
Harmony, etc., where each side contains instrumental and vocal versions of
the same selection, with the beginnings of the two grooves marked "A" and
"B" in the wax at the outer rim to let the user know where to place the
needle.  In that case, the two tracks were definitely not intended to be a
"puzzle" or to produce a "roulette" effect.  So the "puzzle record" seems
to be a subset of a larger category of discs we could call.... what?
Concentric-spiral discs?

 - Patrick