Music files through the years

Almost all music is distributed today in digital, rather than analog, form. Until recently, most digital music was sold in containers called compact discs. Developed and refined between 1965 and 1985, compact-disc technology swept the consumer market during the late 1980s and early 1990s, displacing almost completely long-play vinyl albums. In the past few years, a new method of distributing digital music has become increasingly popular: transmission of containerless files via the Internet, followed by storage on home computers. Music distributed in this manner typically is replayed either through stereo systems attached to the home computers or through portable devices analogous to the "walkman."
The technology that has made this new method convenient and popular is MP3, an audio compression file format. Musical files compressed using MP3 occupy approximately 1/12 of the disk space occupied by uncompressed files, enabling them to be transmitted faster and stored more easily. Two groups have embraced MP3 technology especially enthusiastically. First, musicians unable to obtain recording contracts with the major record companies have found that, at modest cost, they can record their material in MP3 format and then make it available over the Internet. Second, high-school and college students have discovered that they can obtain on the Internet MP3 copies of most of the songs of their favorite musicians. A high percentage of the MP3 recordings available in this manner were prepared without the permission of the owners of the copyrights in the music.