Richard Knoppow wrote:
Look for _Command Performance_ for an illustration of
how records were made c.1940. This had method continues to
this very day for vinyl records. 45's OTOH, were made by
injection molding.

Back in the seventies, if you wanted a 7" pressed you could either get a
vinyl pressing (like an LP) or an injection-molded styrene disk. For large
runs, the styrene pressings were considerably cheaper, so the big labels
used them almost exclusively. But, the vinyl pressings lasted a lot longer
and the distortion when they wore out wasn't quite as horrible, so they
sometimes were used for DJ promo discs and small releases.

None of the styrene systems are still running as far as I know, so if you
get a 7" pressing done today, it will be on standard vinyl.

A very well thought out record system but
RCA just did not get the point that people wanted continuous
records and didn't like record changers. The CBS Lp was a
makeshift. Too bad RCA was so hide-bound about a lot of
things.

Well, the thing is that at the time, the vast majority of record sales
were singles. And really, this continued until the early 1970s for
pop music. A big discussion of the economics of singles vs. LP records
can be found in Jim Eargle's original JAES article in the forties.

The LP was a huge advantage for classical recordings and it totally changed
the form of jazz to be able to make a cut longer than one side of a 78. But
the 45 sure had a lot of popularity in the pop music world for very long
because they were very cheap to make, and because the form of pop music was
such that people wanted one song at a time.

The CD Single flopped mostly because it was very expensive.... you could
get the full album for only a bit more than the single, and so there wasn't
a whole lot of demand for the single. But now in the age of digital downloads
we are seeing a real resurgence in singles sales.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."