The CD

The Compact Disc is a spin-off of Laserdisc technology.Sony first publicly demonstrated an optical digital audio disc in September 1976. In September 1978 they demonstrated an optical digital audio disc with a 150 minute playing time. Technical details of Sony's digital audio disc were presented on March 13–16, 1979, in Brussels.

On March 8, 1979 Philips publicly demonstrated their prototype of a optical digital audio disc at a press conference in the Netherlands

Later in 1979, Sony and Philips set up a joint task force to design a new digital audio disc. The research pushed forward laser and optical disc technology that began by Philips and Sony in 1977 and 1975, respectively.

After a year of experimentation, the taskforce produced the Red Book, the Compact Disc standard. Philips contributed the general manufacturing process, based on video Laserdisc technology. Philips also contributed the (EFM) process, which offers both a long playing time and a high resilience against disc defects such as scratches and fingerprints, while Sony contributed the error-correction method, CIRC.

The Compact Disc was "invented collectively.
The first test CD was in Germany, by Polydor Pressing Operations. The disc contained a recording of Richard Strauss's Eine Alpensinfonie, played by the Berlin Philharmonic.The first public demonstration was on the television program Tomorrow's World when The Bee Gees' album Living Eyes (1981) was played. In August 1982 the real pressing was ready to begin, not far from the place where Emil Berliner had produced his first gramophone record 93 years earlier. The first album released on CD was Billy Joel's 52nd Street, that hit the market alongside Sony's CD player on October 1, 1982.

The following year on March 2, 1983 CD players and discs were released in the U.S. and other markets. The new audio disc was readily received, especially in the classical music and audiophile communities. As the price of players gradually came down, the CD began to gain popularity in the larger popular and rock music markets. The first artist to sell a million copies on CD was Dire Straits, with its 1985 album Brothers in Arms.

The first major artist to have his entire catalogue converted to CD was David Bowie, whose 15 studio albums were made available by RCA Records in February 1985, along with four Greatest Hits albums. In 1988, 400 million CDs were manufactured by 50 pressing plants around the world.

The CD was planned to be the successor of the gramophone record for playing music, rather than primarily as a data storage medium. From its origins as a musical format, CDs have grown to encompass other applications. In June 1985, the computer readable CD-ROM (read-only memory) and, in 1990, CD-Recordable were introduced, also developed by both Sony and Philips. The CD's compact format has largely replaced the audio cassette player in new automobile applications, and recordable CDs are an alternative to tape for recording music and copying music albums without defects introduced in compression used in other digital recording methods. Other newer video formats such as DVD and Blu-ray have used the same form factor as CDs, and video players can usually play audio CDs as well. With the advent of the MP3 in the 2000s, the sales of CDs has dropped in seven out of the last eight years. In 2008, large label CD sales dropped 20%,although independent and DIY music sales may be tracking better according to figures released March 30, 2009.