9781422277386

recorded music. Starting in the 1970s, technology companies began to create digital recordings. Instead of trying to reproduce the sound waves on tape or vinyl, they turned the sound waves into bits, which a computer interprets as an electrical signal going on or off. Digi- tal recording eliminated some of the noise that was picked up during analog recordings. At first, some companies recorded music digitally but then transferred the music to analog tape. By the 1980s, the recording and playback could both be done digitally. The first common digital recordings were sold on compact discs (CDs). A laser in the player read the digital information that made up the music. Unlike records and tapes, the discs were hard to damage. They also could hold more music than a record. The CD introduced people around the world to the idea of digital music. And portable players let them take the music wherever they went. Compression Revolution B y the early 1990s, several technology companies had developed a format to record digital sound in smaller files. MP3 eliminated some data in a digital recording that contained sounds beyond what humans can hear. This compression meant that a song recorded in MP3 took up much less space on a computer than an original record-

CDs were a revolution . . . until they, too, were replaced.

1: The Growth of Digital Music

13