According to the Grove Dictionary of Music and Musicians, sonata form is "the most important principle of musical form, or formal type, from the Classical period well into the 展开

Monothematic expositions
It is not necessarily the case that the move to the dominant key in the exposition is marked by a new theme. … 展开

The term sonata is first found in the 17th century, when instrumental music had just begun to become increasingly separated from vocal music. The original meaning of the term (derived from the … 展开

Sonata form shares characteristics with both binary form and ternary form. In terms of key relationships, it is very like binary form, with a first half moving from the home key to the dominant and the second half moving back again (this is why sonata form is sometimes … 展开

A sonata-allegro movement is divided into sections. Each section is felt to perform specific functions in the musical argument.
• It may … 展开

The standard description of the sonata form is:
Introduction
The introduction section is optional, or may be reduced to a … 展开

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'. … 展开