Elsie's the Sunday monkey!

You know how the Sunday monkey won't play piano song*? The SO and I were talking tonight, and he posited that the Sunday monkey won't play because he can't - a tragic lack of education. But then I realized that it was the Sunday monkey, which was a clear reference to Elsie Dinsmore, who famously (well, famously if you've read Elsie Dinsmore and its sequels) refused to play the piano for her father on a Sunday, because it was in clear violation of Sabbath rules.
So then the mysterious identity of the Sunday monkey was clear!
* and yes, I know the line is sont des mots qui vont tres bien ensemble, tres bien ensemble. But the SO taught me the "Sunday monkey won't play piano song" line, which always amuses me.