Throughout the history of recorded sound, technological changes have periodically reshaped the music industry. One such change was the introduction of the 33¹⁄3-rpm long-playing record (LP; see entry under 1940s—Music in volume 3) and the 45-rpm "single" in 1948. Recorded at speeds of thirty-three and one-third and forty-five revolutions per minute, vinyl records improved the way people listened to music and they offered new opportunities for musical innovation. The introduction of the compact disc (CD) in 1983 was another momentous change. By the late 1980s, the compact disc had almost completely replaced vinyl records, which could become scratched or worn out. Compact discs used digital technology to take sound and convert it to samples that could be read by a laser beam of light. The digital coding could then be placed on a 4¹⁄2 inch disc.

A number of reasons are responsible for the success of CDs: they are...