This discussion brought up a Conservatory memory for me.  We were deep
into an analysis of Beethoven's Piano Concerto #1 in C.  About three
minutes into the 3rd Movement Rondo-Allegro, there is a totally lunatic
Ludwig moment; it lasts about 2 minutes before he goes back to the A
section.

I remember asking the professor what she thought about it.  It sounds
like he's doing a parody of his own work with a jazzy thang added.
Anyway, we came to no conclusion, but it was fun.  I think the whole
last movement has a wonderful playfulness that is in the same vein as
ragtime. It will certainly cheer you up to hear it.

Claudine Jones
San Francisco