Sonata Form - Sonata Form in Concerti

Sonata Form in Concerti

An important variant on traditional sonata-allegro form is found in the first movement of the Classical concerto. Here, the sonata-allegro's customary 'repeated exposition' is replaced by two different but related sections: the 'tutti exposition' and the 'solo exposition'. Prototypically the 'tutti exposition' does not feature the soloist (except, in early classical works, in a 'continuo' role), and does not contain the decisive sonata-exposition modulation to the secondary key. Only when the 'solo exposition' is under way does the solo instrument assert itself and participate in the move to (classically) the dominant or relative major. The situation is only seemingly different in the case of such late classical works as Beethoven's Fourth and Fifth Piano Concertos, where the soloist is heard at the outset: as the later unfolding of those movements makes clear, the opening piano solo or early piano flourishes actually precede the start of the exposition proper.

A structural feature that the special textural situation of the concerto makes possible is the 'ownership' of certain themes or materials by the solo instrument; such materials will thus not be exposed until the 'solo' exposition. Mozart was fond of deploying his themes in this way.

Towards the end of the recapitulation of a concerto movement in sonata form, there is usually a cadenza for the soloist alone. This has an improvisatory character (it may or may not actually be improvised), and, in general, serves to prolong the harmonic tension on a dominant-quality chord before the orchestra ends the piece in the tonic.