The LP (from "long playing" or "long play") is an analog sound storage medium, a phonograph record format characterized by a speed of 33 1⁄3 rpm, a 12- or 10-inch (30- or 25-cm) diameter, and use of the "microgroove" groove specification. Introduced by Columbia in 1948, it was soon adopted as a new standard by the entire record industry. Apart from a few relatively minor refinements and the important later addition of stereophonic sound, it has remained the standard format for record albums.

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