In the name of Music Appreciation or something equally vapid, most
people learn that the first movement of a sonata is usually in Sonata
Allegro form, consisting of theme A in the tonic key, theme B in the
dominant, followed by a development section, and culminating in a
recapitulation of theme A, still in the tonic, and theme B, now also in
the tonic. Pretty predictable, thus pretty uninteresting.
With
the invention of the piano, however, whether a theme was in the key of C
(no black keys) or G (one particularly unsettling black key) made a
huge difference. I found this out while studying a Mozart sonata when a
theme in C major was so transformed when it appeared in G that I could
hardly play it: the single black key so utterly altered the balance of
tones as to make it entirely new.
I find this inherently dramatic, the opposite of predictable.
What
if the purpose of the first movement is to present a cast of
characters, including a masked villain lurking behind a pillar, waiting
to pounce on the suspecting soprano? What if the action is not in the
elements that we would identify as obvious themes but in those at the
bottom of the texture?
