Gypsy Rose Lee
I was rather surprised by the big billing Gypsy Rose Lee received for her quite small role as the "dance instructor". Of course, she was most famous as a stripper and had only a very modest (no pun intended!) career in the movies in her youth; I guess because the Broadway musical GYPSY made her seem like a bigger star in the 1960's.
And how cool is it that "Mama Rose" Rosalind Russell (from the Gypsy movie) gets to work with the real Gypsy here!!