In his Essays in Musical Analysis: Chamber Music, Donald Tovey discusses the makeup of the final variation of Bach’s Goldberg Variations. After the composition’s crowning achievements in counterpoint, symmetry, dance, and technicality, Bach decides to write a “quodlibet” (Latin for “whatever”). “The thirtieth variation is a ‘Quodlibet’; that is, a contrapuntal hotch-potch of popular tunes. In Bach’s time, when the tunes were widely known, the result must have been very amusing.”
According to Tovey, the two tunes are “Kraut und Rüben haben mich ver tricben”, tr. “Cabbage and turnips have driven me away” and “Hätt’ mein’ Mutter Fleisch gukocht, So wär ich länger g’blieben” tr. “If my mother’d cooked some meat, I might have stopped longer.” At least, according to Tovey. Who knows if that’s an accurate translation.
In the outtakes to the 1955 recording of the Goldberg, Glenn Gould chats away about the cultural phenomenon of the quodlibet, how it was common household activity in Bach’s time. A family for evening entertainment might sit around a fire and compete to see who could compose the best quodlibet from the craziest tunes.
fermenting notes 
Do it, John. The only problem is, you would have to learn some popular music. That might kill you before you could write your quodlibet.
Also, “who knows” if that’s an accurate translation from the German? I do. It’s accurate. (You can know, too, using this handy little device: http://translate.google.com/#de|en| )
Why would Tovey provide an inaccurate translation, anyway?
Dude, Rachel, I was in construction for 6 weeks. I’m almost an Eminem expert, and, you’re right, it almost has destroyed me. Every day, during that 2 hour commute home, listening to cleverly-rhymed obscenities faintly reminiscent of late Classical Latin, I would consolingly hum to myself “6 Days on the road and I’m a-gonna get home tonight.”
So based on the translations, it seems Bach was a carnivore and hated veggies. I’d quodlibet my life on it.