Final answer:
The first movement of Mozart's Piano Concerto in A Major, K. 488, uses a sonata-allegro form, consisting of an exposition, development, and recapitulation, where main themes are introduced, elaborated on, and restated.
Step-by-step explanation:
The form of the first movement of Mozart’s Piano Concerto in A Major, K. 488, is structured as a sonata-allegro form. This form typically consists of three main sections: the exposition, the development, and the recapitulation. During the exposition, the main themes of the movement are introduced.
One is typically in the home key, and the other in a related key. The development section elaborates on these themes, often moving through several different keys. Finally, the recapitulation returns to the themes as they were originally presented but typically modifies the second theme to stay in the home key, eliminating the modulation that occurred in the exposition.
This form was very common in classical concertos of the time and Mozart was a master of refining and utilizing it. Mozart's Piano Concerto in A Major is particularly admired for its expressive depth and subtle melodies.