Columbia first vinyl LP 33-1/3 - June 21, 1948

   June 21, 1948 - Columbia launched the vinyl 12-inch 33-1/3 rpm album.

   In June 1948, Columbia introduces the long-playing (LP) record with the microgroove,
which plays at 33 1/3 revolutions per minute. Until this time, albums consisted of collec-
tions of 12-inch 78-rpm discs that featured one or two selections on each side.

  The first microgroove LP pressing released by Columbia was
Philharmonic-Symphony Orchestra Of New York -
Mendelssohn: Concerto In E Minor For Violin And Orchestra Op. 64
 -- Columbia Masterworks - ML 4001

en.wikipedia.org/wiki/LP_record

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