Forms · Unit 1: How form works
Binary form
is the simplest plan in two parts. The first half sets out from the home key and travels to a new one; the second half sets out from there and finds its way home. Each half is usually played twice, which gives the plan A A B B.
In a major key the first half usually ends in the dominant; in a minor key it often ends in the . The second half begins away from home, often with the opening idea in the new key, and closes in the tonic. When the opening tune also returns near the end, the form is called .
Binary form was the standard shape for Baroque dances, the allemandes, courantes, sarabandes and gigues in the suites of Bach and Handel. Classical composers kept it inside larger movements: each half of a minuet, and of its trio, is usually a small binary form.
ScarlattiKeyboard Sonata in D minor, K. 141Domenico Scarlatti wrote 555 keyboard sonatas, almost all of them single movements in two halves. This one, in D minor, opens with fast repeated notes that many hear as a guitar or a mandolin, and later the hands cross over each other at speed. Scarlatti spent most of his working life at the courts of Portugal and Spain, and Spanish dance rhythms colour the music.
ScarlattiKeyboard Sonata in D minor, K. 141Here the second half begins: the opening idea returns, varied, away from home. From this point the music works its way back to D minor.
Listen for the end of the first half. The music settles in its new key, stops, and then the whole half is played again. When the second half starts, you hear the opening idea once more, but in a different light.