It's everything you ever wanted: Marty Feldman, Madeline Kahn, and Gene Wilder all vigorously bunny-hopping in an attic together. From The Adventures of Sherlock Holmes' Smarter Brother (not Mycroft but the jealous Sigerson), which is not at all bad!
I knew there was a reason I always used to mix up Madeline Kahn and Bernadette Peters; the reason was that the universe was going to give me a duet between the two of them.
It turns out Madeline Kahn learned opera because some old Italian man who visited the Bavarian restaurant in upstate New York where she worked as a singing waitress used to shout "SING MADAME BUTTERFLY" at her from the audience, so never forget that life may still have a few surprises in store for you too.
The question has always been, for this series, "How long do I wait before I give them the Blazing Saddles/Clue scenes I know everyone's really here for?" And I think you've waited long enough, and been good.
Surely there is a lesson we can all glean from Madeline's response to the obscene caller. (Does anyone make obscene calls nowadays, or is that a plague that has been lifted from this sorry earth, now that everyone has Caller ID and also no one makes phone calls?)