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.
Album
The Compact Cassette was a popular medium for distributing pre-recorded music in the late 1970s through to the 1990s. The very first "Compact Cassette" was introduced by Philips in August 1963 in the form of a prototype. Compact Cassettes became especially popular during the 1980s after the advent of the Sony Walkman, which allowed the person to control what they listened to. The Walkman was convenient because of its size, the device could fit in most pockets and often came equipped with a clip for belts or pants. Compact cassettes also saw the creation of mixtapes, which are tapes containing a compilation of songs created by any average listener of music. The songs on a mixtape generally relate to one another in some way, whether it be a conceptual theme or an overall sound. The compact cassette used double-sided magnetic tape to distribute music for commercial sale. The music is recorded on both the "A" and "B" side of the tape, with cassette being "turned" to play the other side of the album. Compact Cassettes were also a popular way for musicians to record "Demos" or "Demo Tapes" of their music to distribute to various record labels, in the hopes of acquiring a recording contract. The sales of Compact Cassettes eventually began to decline in the 1990s, after the release and distribution Compact Discs. After the introduction of Compact discs, the term "Mixtape" began to apply to any personal compilation of songs on any given format. Recently there has been a revival of Compact Cassettes by independent record labels and DIY musicians who prefer the format because of its difficulty to share over the internet.