The Sonata-allegro Form
As distinguished from the sonatine-form, with
its two Divisions, this larger species, based upon precisely the same
structural idea, has three Divisions,--the Exposition, a middle
Division called the Development (growing out of the brief interlude of
the sonatine-form), and the Recapitulation. The diagram (the keys of
which correspond to the plan of Beethoven, op. 14, No. 2, first
movement) is as follows:
Exposition. Middle Div. Recapitulation.
---------------------- ------------- -------------------------
Pr. Sub. Codetta. Development, Phr. Sub. Codetta
Th. Th. various keys, Th. Th. and Coda.
---------------------- ending with -------------------------
G maj. D maj. D maj. Retransition. G maj. G maj. G maj.
Compare this diagram, also, with that of the Third Rondo-form, and
note, accurately, the points of resemblance and contrast.
Compare it, further, with the diagram of the sonatine-form, on page
122. It will be observed that here the Recapitulation does not follow
the Exposition at once, as there, but that a complete middle division
intervenes, instead of the brief interlude or re-transition; from which
the student may conclude that the sonatine-form gradually grows into
the sonata-allegro form, as this interlude becomes longer, more
elaborate, and more like an independent division of the design. Or
inversely, and perhaps more correctly, the sonata-allegro becomes a
sonatine-design by the omission (or contraction) of the middle
Division.