The Compact Disc (also known as a CD) is an optical disc used to store digital data. It was originally developed to store and playback sound recordings exclusively, but later expanded to encompass data storage (CD-ROM), write-once audio and data storage (CD-R), rewritable media (CD-RW), Video Compact Discs (VCD), Super Video Compact Discs (SVCD), PhotoCD, PictureCD, CD-i, and Enhanced CD. Audio CDs and audio CD players have been commercially available since October 1982. Standard CDs have a diameter of 120 millimetres (4.7 in) and can hold up to 80 minutes of uncompressed audio or 700 MB (700 × 220 bytes) of data. The Mini CD has various diameters ranging from 60 to 80 millimetres (2.4 to 3.1 in); they are sometimes used for CD singles, storing up to 24 minutes of audio or delivering device drivers. CD-ROMs and CD-Rs remain widely used technologies in the computer industry. The CD and its extensions are successful: in 2004, worldwide sales of CD audio, CD-ROM, and CD-R reached about 30 billion discs. By 2007, 200 billion CDs had been sold worldwide. Compact Discs are increasingly being replaced or supplemented by other forms of digital distribution and storage, such as downloading and flash drives, with audio CD sales dropping nearly 50% from their peak in 2000.
History and Future
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, and with specifications of 44,056 Hz sampling rate, 16-bit linear resolution, cross-interleaved error correction code, that were similar to those of the Compact Disc introduced in 1982. Technical details of Sony's digital audio disc were presented during the 62nd AES Convention, held on March 13–16, 1979, in Brussels. On March 8, 1979 Philips publicly demonstrated a prototype of an optical digital audio disc at a press conference called "Philips Introduce Compact Disc" in Eindhoven, Netherlands. On March 6, 2009, Philips received an IEEE Milestone with the following citation: "On 8 March 1979, N.V. Philips' Gloeilampenfabrieken demonstrated for the international press a Compact Disc Audio Player. The demonstration showed that it is possible by using digital optical recording and playback to reproduce audio signals with superb stereo quality. This research at Philips established the technical standard for digital optical recording systems." Sony executive Norio Ohga, who later became the CEO and chairman of Sony, was convinced of the format's commercial potential, and pushed further development despite widespread skepticism. Later in 1979, Sony and Philips Consumer Electronics (Philips) set up a joint task force of engineers to design a new digital audio disc. Led by Kees Schouhamer Immink and Toshitada Doi, the research pushed forward laser and optical disc technology that began independently by Philips and Sony in 1977 and 1975, respectively. After a year of experimentation and discussion, the taskforce produced the Red Book, the Compact Disc standard. Philips contributed the general manufacturing process, based on video Laserdisc technology. Philips also contributed eight-to-fourteen modulation (EFM), 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 Story, told by a former member of the taskforce, gives background information on the many technical decisions made, including the choice of the sampling frequency, playing time, and disc diameter. The taskforce consisted of around four to eight persons, though according to Philips, the Compact Disc was thus "invented collectively by a large group of people working as a team." The first test CD was pressed in Langenhagen near Hannover, Germany, by the Polydor Pressing Operations plant. The disc contained a recording of Richard Strauss's Eine Alpensinfonie (in English, An Alpine Symphony), played by the Berlin Philharmonic and conducted by Herbert von Karajan. The first public demonstration was on the BBC 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 in the new factory, not far from the place where Emil Berliner had produced his first gramophone record 93 years earlier. By now, Deutsche Grammophon, Berliner's company and the publisher of the Strauss recording, had become a part of PolyGram. The first CD to be manufactured at the new factory was The Visitors (1981) by ABBA. The first album to be released on CD was Billy Joel's 52nd Street, that reached the market alongside Sony's CD player CDP-101 on October 1, 1982 in Japan. Early the following year on March 2, 1983 CD players and discs (16 titles from CBS Records) were released in the United States and other markets. This event is often seen as the "Big Bang" of the digital audio revolution. The new audio disc was enthusiastically received, especially in the early-adopting classical music and audiophile communities and its handling quality received particular praise. 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. Well it's time for us to say farewell to CD. MP3 revolution has finally been dealt a killing blow to a compact disc - CD, which will be produced this physical medium just until end of 2012. year. The public hasn't really been into music CDs for quite some time, but now it's reportedly official. Yes, major record labels will finally cease production of CDs next year. This definitely doesn't feel like any big news flash, and like any lingering death, it's not surprising when it finally comes. As SideLine reports, what's left of the major labels will abandon CDs for good by the end of 2012. As expected, they will shift to downloads and streaming exclusively, which is where music has been moving along anyways. The music business is usually pretty slow to react to things, and at one point they were thinking music by subscription would save everything, so now it's obvious to everybody that the writing is clearly on the wall. With the collapse of the huge chains stores like Tower and Virgin, Amazon will reportedly be the only (major) entity left carrying CDs, and as SideLine continues, CDs will only be made in the future for limited edition releases. Unsurprisingly, SideLine tried to reach EMI, Universal and Sony for comment, but all three labels declined to respond. When CDs finally broke through in the '80's with the Beatles releases, the sound quality was indeed terrific, and we all got used to the format change from vinyl, some faster than others. Now CDs bring reactions of disgust from modern day music fans who grew up in the download age, and as we just reported on TG, vinyl's been making a hell of a comeback these days as well. As underground metal label Relapse Records founder Matt Jacobson told me, "About a year ago, I thought I could see a day where it's only vinyl and digital, and it's actually happening sooner than I thought. CDs are so disposable, I have so many of them, they get in the way. The digital is great because it's convenient, and it doesn't take up twenty-five shelves of space."