The long-playing, or LP, format for sound recordings was one of the most important innovations in entertainment technology after World War II. In addition to extending the duration of recordings, the microgroove long-playing vinyl record brought new levels of fidelity to recorded sound. Its wide acceptance by listeners worldwide ensured that this was to be the primary format for sound recordings from its commercial introduction in the 1940s until the emergence of digital recording in the 1980s.

The search for a longer playing format for sound recordings began immediately after the invention of the phonograph in 1877. The technology was aimed at the business user, and the two-to three-minute playback of the cylinder was too short for the phonograph's intended use as a dictating machine. One of the major advantages of the disc over the cylinder format was that it was easier to extend the play of...