A look at and listen to a RCA Victor Program Transcription record, as mentioned by ‪@Techmoan‬ in his video about the LP vs. 45 format war, which was the first longplaying 33⅓ RPM format introduced to the public in 1931, but was stymied by the Great Depression, an early vinyl formulation that wore out quickly, and sound quality inferior to 78 RPM records of the day. The format was discontinued in 1933, but some of the Program Transcription records remained in RCA Victor's catalog until 1939.

Note that this was not actually the first longplaying record format; that was Pathé's giant 20inch, 60 RPM Theatre Disc of 1913:    • Pathé Theatre Disc, 50 cm diameter, c...  

The highfidelity 78 RPM RCA Victor record from 1932 that I played a brief clip of:    • 1932, Look Who's Here, Ted Weems Orch...