Recorded April 24, 1980, for an HBO concert special. The tapes were lost for decades until Ronstadt's manager located them. Ronstadt then chose 12 performances from the show for release. Her first official album of "new" (or, at least, unreleased) performances since her retirement in the early 2010s.
@kab2112 Quite possible that the bootleg reflects the complete set list, though the recording would need to be compared side-by-side with Live in Hollywood to see if it's the exact same show. I'd be surprised if she only did one Hollywood show - I could see her doing a runthrough before the cameras rolled. What's bizarre is Rhino has released a number of clips from the special to YouTube, and they look amazing, yet there's no indication that the special is going to be released on DVD. Maybe there's some rights issue going on with HBO that's allowing commercial distribution of the audio only, which is a shame as this performance captured Linda in her transition period between pop stardom and moving into more esoteric things like opera (I think she started Pirates of Penzance only a few months later) and (Get Closer notwithstanding) big band music. (Edit: accidentally uploaded this comment as a review initially - oops!)
It has been suggested (but not confirmed) to me by the guy I got this from a few years ago that this is the full concert. He said he thought it was recorded in Hollywood 1980