In Andreas Staier recording of Beethoven's Diabelli Variations, there is some weird stuff going on throughout variations 22 and 23 (recording here starts at var 22). It sounds like there's paper between the strings for some parts of var 22 (or a kazoo?), and he borrowed the percussion section of an orchestra for some bits of var 23.
Does anyone know the inside scoop? The buzziness in var 22 seems like a nod to the opening bars of Don Giovanni (indeed, the variation is known as "Allegro molto, alla « Notte e giorno faticar » di Mozart"). It reminded me of the fagotti that back up Leporello during his opening complaint "Notte e giorno faticar". Anything to back up this wild speculation? What about the cymbal crashes apparent in var 23?