On Wed, 25 Oct 2006 20:03:43 -0700, DeserTBoB
wrote:

Columbia kept their Masterworks catalog at 7½ for a couple of
years after they'd slowed the pop catalog ("red label") down, but the
"gray label" stuff eventually went to 3¾ as well...to the howls of
audiophiles everywhere. snip

....as they did when prerecorded consumer tapes went from 2 track to 4
track...which was a bigger drop at the time, due to noisier tape.