Funny record covers.

A record sleeve is the outer covering of a vinyl recording. The sleeve is technically the paper covering that is closest in contact to the surface of the recording, as in “dust sleeve”, “liner” and “album liner”. The term has come to be synonmous with “record jacket” and “album jacket”, which is the outermost cardboard covering of a vinyl LP. The vinyl LP jacket and the 7″/12″ sleeve are the areas to receive considerable attention to graphic design, and will contain the most important and pertininent information about the recording (manufacturer, artist, title of recording, and contents), assuming there is no visible record label with such information. The term “album liner” (or “record liner”) led to the expression “liner notes”.

A gramophone record (also phonograph record, or simply record) is an analogue sound storage medium consisting of a flat disc with an inscribed modulated spiral groove starting near the periphery and ending near the center of the disc. Gramophone records were the primary medium used for commercial music reproduction for most of the 20th century. They replaced the phonograph cylinder as the most popular recording medium in the 1900s, and although they were supplanted in popularity in the late 1980s by digital media, they continue to be manufactured and sold as of 2008. Gramophone records remain the medium of choice for some audiophiles, and specialist areas such as electronica.

The normal commercial disc is engraved with two sound bearing concentric spiral grooves, one on each side of the disc, running from the outside edge towards the centre. Since the late 1910s, both sides of the record have been used to carry the grooves. The recording is played back by rotating the disc clockwise at a constant rotational speed with a stylus (needle) placed in the groove, converting the vibrations of the stylus into an electric signal (see magnetic cartridge), and sending this signal through an amplifier to loudspeakers.

The majority of records are pressed on black vinyl. The colouring material used to blacken the transparent PVC plastic mix is carbon black, the generic name for the finely divided carbon particles produced by the incomplete burning of a mineral oil based hydrocarbon. Carbon black increases the strength of the disc and renders it opaque…

Vitaphone

The first prototype of the LP were the phonograph discs used in the Vitaphone sound motion picture process, developed by Western Electric and introduced in 1926. The four-minute limit of a conventional 78 rpm disc was not acceptable. The discs needed to play at least 11 minutes, long enough to accompany a thousand-foot reel of 35 mm film at 24 frames per second. The diameter of the disc was increased from 10 inches (25 cm) to 16 inches (41 cm), and the speed was slowed to 33⅓ revolutions per minute. The main differences from later LPs were that the stylus moved from the center of the Vitaphone disc outward, and a standard-width groove was used, similar to 78s, requiring a relatively heavy steel needle for recording and playback. By 1930, all movie studios were recording on optical soundtracks, although they continued to distribute Vitaphone versions of their films to certain theaters as late as 1936.

Radio transcription discs

From the mid-1920s until the adoption of magnetic tape recordings in the late 1940s and early 1950s, the radio industry used 16-inch and 12-inch discs, revolving usually at 33⅓ rpm, to transcribe radio broadcasts, either for archival purposes or to distribute copies to individual radio stations. These records were either aluminum core with lacquer, glass with lacquer (when there were aluminum shortages during World War II), or later, vinyl

RCA Victor

RCA Victor introduced an early version of a long-playing phonograph record in September 1931. The disc played at 33⅓ revolutions per minute, used almost double the number of grooves of a 78 rpm disc, could hold up to 15 minutes per side, and was pressed on a new composition that reduced the surface noise of the needle. 10- and 12-inch versions were released, and used one or both sides of the disc. Beethoven’s Fifth Symphony, performed by the Philadelphia Symphony Orchestra under Leopold Stokowski, was the first recording. The New York Times wrote, “What we were not prepared for was the quality of reproduction.…incomparably fuller.” The invention lasted two years before being pulled off the market. Overall record sales in the U.S. had crashed from a high of $105.6 million in 1921 to $5.5 million in 1933, due to competition from radio and the effects of the Great Depression.
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