Missing Star Wars Music

Does anyone have the piece of music that’s missing from the soundtrack release of Star Wars – Return Of The Jedi? The music is heard twice in the movie and yet it has never been released in any form, even when the "entire" soundtrack was released on CD.
The music is first heard where Chewbacca is being carted off to Jabba the Hutt’s dungeon.
The second time it is heard about ten minutes later in the film when Jabba the Hutt’s desert sail barge is crossing the dunes to the sarlacc pit. On both occasions the music is being played by Jabba the Hutt’s band.
I wonder if anyone has a copy of this elusive track….there may be a bootleg of it kicking around someplace??? Otherwise somebody may have some information as to why this music is missing.