The word bootleg usually raises eyebrows but for some, it can make for an interesting item for some collections.  Check out this article for more details.

“It is a real Holy Grail, as it is May 4, 1971 Odense show that has been hoarded for over 51 years! The biggest surprise, apart from very good sound quality, is that the tape features live versions of Four Sticks and Gallows Pole, performed just a day prior on the famous Copenhagen show on May 3, 1971,”