Speaking of the jazz bar, I found footprints leading from the jazz bar to the opera house. There were two sets, one very large and a smaller set. And before you ask, no, I couldn't determine what size they were.

Closer to the jazz bar, I found this. [It's a short golden chain!] It looks as though it came from Olivert's coat.

The footprints were also uninterrupted - no signs of a struggle or anything else strange.