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.
Cassette tape
The mass production of blank (recordable) Compact Cassettes began in 1964 in Hanover, Germany. Prerecorded music cassettes (also known as "Music-Cassettes", and later just Musicassettes; M.C. for short) were launched in Europe in late 1965. The Mercury Record Company, a US affiliate of Philips, introduced M.C. to the US in July 1966. The initial offering consisted of 49 titles.
However, the system had been designed initially for dictation and portable use, with the audio quality of early players not well suited for music. Some early models also had an unreliable mechanical design. In 1971, the Advent Corporation introduced their Model 201 tape deck that combined Dolby type B noise reduction and chromium(IV) oxide (CrO) tape, with a commercial-grade tape transport mechanism supplied by the Wollensak camera division of 3M Corporation. This resulted in the format being taken more seriously for musical use, and started the era of high fidelity cassettes and players.