I'd seen the cover to the classic folk album "Doc Watson at Gerdes Folk City" before and Gerdes is a common-enough German name that I knew it likely wasn't a relative. But it was in the category of "a fun thing to have your last name on". Now I've discovered that it's certainly NOT a relative, because the album cover is missing an apostrophe. (To be fair, so were the club's own flyers.) It's "Gerde's Folk City". Punctuation matters, people!