Which term is NOT associated with the structure of sonata form?

The term that is not associated with the structure of sonata form is "Allegretto." Sonata form traditionally consists of three main sections: the Exposition, Development, and Recapitulation.

In the Exposition, the main themes are presented; the Development section expands and explores these themes; and the Recapitulation brings back the original themes, usually in the home key. This framework is essential in classical composition, particularly in symphonies and sonatas.

"Allegretto," however, refers to a moderate tempo marking, indicating a speed of music, rather than a structural component within sonata form. It does not describe any part or function of the sonata form, making it an unrelated term in this context.