[78-L] RCA Victor sets - M AM DM designations.

[Thomas Stern]

  This has been discussed before, could someone refresh my memory:
  I know there are MANUAL and AUTOMATIC sequence sets, but didn't realize
the records
also had different catalog numbers, and what is the third variation???
  [This question arises from seeing the booklet in DM 566 Peter & the Wolf,
which lists
    M 566 (15442-15444), AM 566 (15445-15447), DM 566 (16122-16124).  The
records in DM 566 have
    numbers in the wax and in parens on the labels 035433-035438. The album
is stamped on the cover
    with the credits, no other notes, but includes a 4pp insert; I've seen
other issues of this album
    with color illustrated cover and notes inside the covers, don't know
catalog nos,.]
  Thanks!
  Best wishes, Thomas.