Although not billed, Tom Waits performed at the August 18th show, much to the displeasure of the audience:
“Unfortunately Tom was booed off the stage before he could do a whole set, presumably because the Eagles fans were more accustomed to sweet than dour. The headliners were not pleased, and made a big point of emphasizing the identity of the composer of ‘Ol 55’ when the time came.” (Ken Langford, Tom Waits Library)
It’s interesting that Waits would perform at this show since he disliked the Eagles version of his song and said so publicly in early 1975 (read more here). The next year his comments about the band were even more harsh when he told a reporter that their albums were only good for “keeping dust off your turntable.” One can’t help but wonder if getting booed at this concert added to his contempt for the band.