75 years ago RCA (United States) released the first series of 45-RPM records

Playback speeds of the early records varied. By the beginning of the 20th century, the international standard 78-rpm was adopted as a compromise between the quality of playing back and time of sounding. The speed of 16-rpm was used in the 1930s-1950s as well – to record conversational speech, where the duration of sounding material was crucial, and not the quality of playing back.

In 1948, Columbia (USA) introduced a new standard for playback speed – 33 1/3 rpm. The records sounding at this speed were called “Long Play” (LP).

This speed remains the main standard in the production of vinyl records nowadays. Coupled with the compaction of sound tracks, it allowed achieving 15-17 minutes duration on one side of the 10" record. Later, due to the development of technology and against longevity of sounding, the duration was increased to 20-25 minutes in the 1960s-1970s; and up to 30 minutes in the 1980s. The main reason for the development of a new standard was competition with tape recorders, where the duration of playing back was limited only by the length of the magnetic tape.

On March 31, 1949 RCA (USA) developed another speed standard – 45 rpm.

Although it was originally intended for the release of all records, later it became a standard basically for singles, i.e. records containing one or several songs (often one-sided, for playing in jukeboxes), which were released for advertising support during the upcoming tour or before the release of a large record. The 45-rpm records of giant size (12”) that were called maxi-singles appeared in the mid-1970s. The remixes of popular songs and the songs that were not included in the albums were usually published on them.

Throughout the 20th century, gramophone records were modernized, improved, modified, made more and more handy, and in the late 1960s and early 1970s became a collector’s and cult item. This was facilitated by the emergence of rock music, which gathered a lot of fans all round the world, and a lot of people carried the love for this kind of music (and to the record as its storage) through life.

Musical selection dedicated to the 70th anniversary of producing 45 rpm records by the company RCA is posted in the museum Phonotheque.
The history of a 45-RPM record is in the section REVIEW ARTICLES.

Sited: https://zen.yandex.ru/media/zavalinka/gramplastinki-i-ih-raznovidnost-istoriia-vinila-chast-2