出典:Wikipedia
出典:『Wikipedia』 (2011/06/02 14:04 UTC 版)
A gramophone record, commonly known as a phonograph record (in American English), vinyl record (in reference to vinyl), or colloquially, a record, is an analog sound storage medium consisting of a flat disc with an inscribed, modulated spiral groove. The groove usually starts near the periphery and ends near the center of the disc (the opposite of the spiral of pits in the CD medium, which starts near the centre and works outwards). Phonograph records are generally described by the size of their diameter ("12-inch", "10-inch", "7-inch", etc.), the rotational speed at which they are played ("33⅓ r.p.m.", "78", "45", etc.), their time capacity ("Long Playing"), their reproductive accuracy, or "fidelity", or the number of channels of audio provided ("Mono", "Stereo", "Quadraphonic", etc.).