"Mike" wrote ...
I worked at a Kroger store in rural West Virginia (the town of
Madison,
30 miles south of Charleston in the coal fields) in the early 90s and
we had this extremely antiquated in-store music system. The store had
been built in the early 80's and the sound system involved this box
with about 10 large tapes in it. The tapes looked kinda like 8-track
tapes, only they were about 8" by 10" big (but flat, like an 8 track).

We had a system like this at the hospital where I used to work.
One of my jobs was to create new custom tapes for the system.
Was it a continuous loop (like radio carts & auto 8-track)? or
did it have two 10.5-inch reels in the case?, I can't remember.
It must have been reel-to-reel as I don't think a continuous-loop
system would work with 10.5-inch equivalent of tape. And I
don't remember using the special back-lubricated tape for that.

I did another project in the mid 1980s where I made a multi-
language sound track for a slide show and packaged it into
a Fidelipak continuous-loop cart. Five languages alternating
through three of the tracks, and the fourth track dedicated to
the slide-advance tone. Used a modular Telex cart deck and
four playback preamps, one modified with a relay-closure
output for the slide projector. Modified it all for 220v 50Hz
and shipped it (untested @ 220v 50Hz) to Europe where it
played for two weeks without a hitch. Dunno if there is even
a computer-based solution for this today? (Multi-track playback
synced to "slide-show")