ES: forma sonata, I: forma sonata, F: [en] forme de sonate, D: Sonatenform, NL: hoofdvorm, sonatevorm, DK: sonateform, S: sonatform, FI: sonaattimuoto.
A form used frequently for single movements of the sonata, symphony, quartet, etc. A movement written in sonata form falls into three sections called exposition, development and recapitulation. In the exposition the composer introduces some musical ideas, consisting of a number of themes; in the development section the composer `develops' this material, and in the recapitulation the composer repeats the exposition, with certain modifications. The exposition contains a number of themes that fall into two groups, often called first and second subject. Other melodies occurring in each group are considered as continuations of these two. The second theme is in another key, normally in the key of the dominant if the tonic is major, and in the relative key if the tonic is minor.