A bootleg recording is an audio or video recording of a performance that was not officially released by the artist or under other legal authority. The process of making and distributing such recordings is known as bootlegging. Recordings may be copied and traded among fans of the artist without financial exchange, but some bootleggers have sold recordings for profit, sometimes by adding professional-quality sound engineering and packaging to the raw material. Bootlegs usually consist of either unreleased studio recordings, live performances or interviews with an unpredictable level of quality.
The concept of releasing unauthorised performances had been established before the 20th century, but reached new levels of popularity with Bob Dylan's Great White Wonder, a compilation of studio outtakes and demos released in 1969 using low-priority pressing plants. The following year, the Rolling Stones' Live'r Than You'll Ever Be, an audience recording of a late 1969 show, received a positive review in Rolling Stone. Subsequent bootlegs became more sophisticated in packaging, particularly the Trademark of Quality label with William Stout's cover artwork. Compact disc bootlegs first appeared in the 1980s, and internet distribution became increasingly popular in the 1990s.
Changing technologies have affected the recording, distribution, and varying profitability of the underground industry. The copyrights for the song and the right to authorise recordings often reside with the artist, according to several international copyright treaties. The recording, trading and sale of bootlegs continues to thrive, however, even as artists and record companies attempt to provide officially-released alternatives to satisfy the demand.
The word "bootleg" originates from the practice of smuggling illicit items in the legs of tall boots, particularly the smuggling of alcohol during the American Prohibition era. The word, over time, has come to refer to any illegal or illicit product. This term has become an umbrella term for illicit, unofficial, or unlicensed recordings, including vinyl LPs, silver CDs, or any other commercially sold media or material. The alternate term ROIO (an acronym meaning "Recording of Indeterminate / Independent Origin) or VOI (Video....) arose among Pink Floyd collectors, to clarify the recording source and copyright status was hard to determine.