This is why I am enjoying teaching from Richard Taruskin's Oxford History of Western Music this semester (the 17th and 18th-centuries volume):
This is one of the most widely respected American scholarly experts on music history writing about J. C. Bach's Sonata in D major, op. 5 no. 2, first movement. And I love it! It takes a potentially tedious explanation of formal process and gives it a playful turn - not unlike the music under discussion, which was a central example of the Galant style. That style, as my graduate students in a class on Music of the Classical Era have been discussing in great detail, took its elegant melodies, stark contrasts, and overt humor straight from comic opera of the day.
Perhaps Taruskin caught a little of the comic opera bug there!