LP record
A 12-inch LP vinyl record Top: the original LP logo as used by Columbia Records | |
| Media type | Audio playback |
|---|---|
| Encoding | Analog groove modulation |
| Capacity | Originally 23 minutes per side, later increased by several minutes, much longer possible with very low signal level |
| Read mechanism | Microgroove stylus (maximum tip radius 0.001 in or 25 μm) |
| Developed by | Columbia Records |
| Dimensions | 12 inches (30 cm), 10 inches (25 cm), 90–240 g (3.2–8.5 oz) |
| Usage | Audio storage |
| Released | 1948 |
The LP (from long playing or long play) is an analog sound storage medium, specifically a phonograph record format characterized by: a speed of 33+1⁄3 rpm; a 12- or 10-inch (30- or 25-cm) diameter; use of the "microgroove" groove specification; and a vinyl (a copolymer of vinyl chloride acetate) composition disk. Introduced by Columbia Records in 1948, it was soon adopted as a new standard by the entire US record industry and, apart from a few relatively minor refinements and the important later addition of stereophonic sound in 1957, it remained the standard format for record albums during a period in popular music known as the album era. LP was originally a trademark of Columbia and competed against the smaller 7-inch sized "45" or "single" format by RCA Victor, eventually ending up on top. Today in the vinyl revival era, a large majority of records are based on the LP format and hence the LP name continues to be in use today to refer to new records.