I know what you mean, Joe, but the tunes are very different (at least, on first sight). Killigrew's Soiree is 4/4 with a 'scots snap' or 2/4 with a bounce, depending on how you view it. Charladies Ball is a swinging (or swingeing)Viennese waltz. If you start to think about the way the notes move, and the phrases, they begin to seem rather more similar, but probably because they both come out of a tight music hall style than because one is a rewrite with tempo change.