This document provides an overview of various classical music forms including the sonata, sonata allegro form, concerto, symphony, and classical opera. It describes the sonata as a multi-movement work for a solo instrument. The sonata allegro form is explained as having three main sections - the exposition introducing themes, the development section elaborating on themes, and the recapitulation repeating themes. The concerto is defined as a multi-movement work for a solo instrument accompanied by orchestra. The symphony is summarized as a multi-movement work for full orchestra only. Finally, it distinguishes between the serious classical opera style of opera seria and the comic style of opera buffa.