Sonata form is a musical structure commonly used in the first movements of symphonies, sonatas, and chamber music. It typically consists of three main sections: the exposition, where the main themes are introduced; the development, where these themes are explored and transformed; and the recapitulation, where the original themes return, often in the home key. This form allows composers to create contrast and tension through thematic variation and modulation. It provides a framework for organizing musical ideas, making it a fundamental element in the works of composers like Ludwig van Beethoven and Wolfgang Amadeus Mozart.