A bootleg recording is an audio or video recording of a performance not officially released by the artist or under other legal authority. Making and distributing such recordings is known as bootlegging. Recordings may be copied and traded among fans 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 unreleased studio recordings, live performances or interviews without the quality control of official releases.
Who's Zoo compiled early singles and B-sides by the Who, which had not been commercially released in the U.S. Like several Trademark of Quality bootlegs, it featured cover artwork by William Stout.
Kum Back, a collection of recordings by the Beatles in early 1969, appeared before the official release of Let It Be.
The Pink Floyd bootleg The Dark Side of the Moo collected early singles and B-sides. When released, it was the only way to hear the studio version of "Astronomy Domine" in the U.S, as it was not included on the U.S. issue of The Piper at the Gates of Dawn
The Black Album by Prince was withdrawn from sale shortly before its official release date in December 1987, becoming a popular bootleg.
The Rolling Stones' 1969 Tour of the United States took place in November 1969. With Ike & Tina Turner, Terry Reid, and B.B. King as the supporting acts, rock critic Robert Christgau called it "history's first mythic rock and roll tour", while rock critic Dave Marsh wrote that the tour was "part of rock and roll legend" and one of the "benchmarks of an era." In 2017, Rolling Stone magazine ranked the tour among The 50 Greatest Concerts of the Last 50 Years.