Music Chat: Classical Sonata Form Unpacked

There are a million ways to think about classical sonata form, but many involve fairly complicated theoretical constructs that would have been completely unfamiliar to the composers who used it most successfully. Taking as an example the Naxos recording of Haydn's Symphony No. 90, I offer a simpler, but not simplistic, way of understanding how sonata form works in the great classical symphonies and instrumental works.