The roots of this form can be traced to the simple binary form of the baroque era. With binary, the two sections are thematically similar with a sameness of texture and theme throughout the movement. The term sonata originally referred to instrumental music, not a particular form of composition. The Baroque sonata can be traced back to an instrumental song of the late Renaissance called canzon da sonar. This leads eventually to the trio sonata, for four instruments despite its name, which consisted of two melody instruments, a chord playing instrument, and a basso continuo. Along with the trio sonata, there was the solo sonata that was written primarily for a melody instrument and a basso continuo. In the late 1600s, the word sonata was associated with sonate da chiesa, for church, and sonate da camera, for chamber.
With the rejection of complicated Baroque style of music, the classical era came about. The idea of simpler music would appeal to a broader audience, thus making the classical era more popular. The change was not sudden; rather, the Rococo style was like a transition period. Carl Philipp Emanuel Bach was an important character in the changing of styles. The Rococo style was known as an expressive or sensitive style. Baroque music usually remained in the same mood throughout a piece, whereas this new style would sometimes change moods abruptly with highly contrasting ideas. The use of ornaments in music gradually went out with the complicated baroque music. Simpler, more original melodies emerged with this new style. During the Baroque era, instrumental music and vocal music were equally important. This contrasts the Classical era where instrumental music was more prominent than vocal.
Sonata form, or sonata allegro form, consisted of three major sections: exposition, development, and recapitulation. Exposition presented the main theme of the movement in the tonic key. Then the theme transitioned by a bridge