An 8-track tape is a hard plastic cartridge about the size of an external modem that houses a continuous loop of non-digital (analog) audio data stored on magnetic tape. William Powell Lear, founder of Learjet, invented and patented the 8-track tape and its corresponding player in 1963, when he was looking for a simple, long-playing tape system to install in the business jets that bore his name.
8-track tapes, which can hold up to 45 minutes of sound, were introduced to the general public in 1966 when the Ford Motor Company included 8-track players as a cutting-edge automotive accessory for the Ford Mustang. The music recording industry quickly saw the potential for a lucrative home player market and by the early 1970's, 8-track tapes were replacing vinyl long-playing (LP) record albums as the dominant format in pre-recorded music. Their light-weight plastic casings made them ideal for travel -- and unlike vinyl records, 8-track tapes didn't warp or skip.
By the early 1980s, advances in tape technology and noise reduction made the even smaller compact cassette the system of choice and by 1983, record labels ceased production of pre-recorded 8-track tapes altogether. Today, the adjective "8-track" is synonymous with "quickly obsolete".