Records, used to record sound, were invented in 1877 by Thomas Alva Edison, who invented the first machine to record and play back sounds (the phonograph or record player). Early records were cylindrical, but flat disks soon replaced them.
Edison’s first phonograph used tin-covered cylinders to record vibrations of sound that were focused by a horn-like device onto a diaphragm; the diaphragm vibrated and transmitted the vibrations to a stylus (needle), which etched a helical groove onto a rotating cylinder covered with tin foil. The sound could then be played back from the etched cylinder as a needle went along the groove and reversed the process, making the diaphragm vibrate, recreating the original sound. Edison’s first recording was of him saying, “Mary had a little lamb.” The recording cylinders were improved by Charles Sumner Tainter (an associate of Alexander Graham Bell), who made them out of wax.
The first flat, circular record was invented by Emile Berliner (1851-1929), a German-born American inventor, in 1887 (he also invented the gramophone, the machine that played his flat records). Berliner’s records were originally made of glass, then zinc, and later, hard rubber. Berliner founded Deutsche Grammophon and Britain’s Gramophone Co., Ltd.
By 1915, records rotated at a standard 78-rpm (rotations per minute) and were made of shellac (which is very fragile); they were 10 inches in diameter and recorded 4 minutes of sound. The long-playing record (the LP) was invented in 1948 by Columbia Records - it played at 33-rpm and was 10 or 12 inches in diameter. The LP was made from flexible plastic vinyl (vinylite) and not rubber. Using new microgrooves, these records recorded over 20 minutes of sound. In 1949, 7-inch 45-rpm records were introduced.