Compact disc
Compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony and released in 1982. The format was originally developed to store and play only sound recordings (CD-DA) but was later adapted for storage of data (CD-ROM). Several other formats were further derived from these, including write-once audio and data storage (CD-R), rewritable media (CD-RW), Video Compact Disc (VCD), Super Video Compact Disc (SVCD), Photo CD, PictureCD, CD-i, and Enhanced Music CD. The first commercially available audio CD player, the Sony CDP-101, was released October 1982 in Japan.
History of sound recording
The third wave of development in audio recording began in 1945, when the allied nations gained access to a new German invention - magnetic tape recording. The technology was invented in the 1930s, but remained restricted to Germany (where it was widely used in broadcasting) until the end of World War II. Magnetic tape provided another dramatic leap in audio fidelity — indeed, Allied observers first became aware of the existence of the new technology because they noticed that the audio quality of obviously pre-recorded programs was practically indistinguishable from live broadcasts. From 1950 onwards, magnetic tape quickly became the standard medium of audio master recording in the radio and music industries, and led to the development of the first hi-fi stereo recordings for the domestic market, the development of multi-track tape recording for music, and the demise of the disc as the primary mastering medium for sound. Magnetic tape also brought about a radical reshaping of the recording process — it made possible recordings of far longer duration and much higher fidelity than ever before, and it offered recording engineers the same exceptional plasticity that film gave to cinema editors — sounds captured on tape could now easily be manipulated sonically, edited, and combined in ways that were simply impossible with disc recordings. These experiments reached an early peak in the 1950s with the recordings of Les Paul and Mary Ford, who pioneered the use of tape editing and "multi-tracking" to create large 'virtual' ensembles of voices and instruments, constructed entirely from multiple taped recordings of their own voices and instruments. Magnetic tape fueled a rapid and radical expansion in the sophistication of popular music and other genres, allowing composers, producers, engineers and performers to realize previously unattainable levels of complexity. Other concurrent advances in audio technology led to the introduction of a range of new consumer audio formats and devices, on both disc and tape, including the development full-frequency-range disc reproduction, the change from shellac to polyvinyl plastic for disc manufacture, the invention of the 33rpm, 12-inch long-playing (LP) disc and the 45rpm 7-inch "single", the introduction of domestic and professional portable tape recorders (which enabled high-fidelity recordings of live performances), the popular 4-track cartridge and compact cassette formats, and even the world's first "sampling keyboards" - the pioneering tape-based keyboard instrument the Chamberlin, and its more famous successor, the Mellotron.