Final answer:
Haydn wrote 62 keyboard sonatas, known for their inventive melodies, expressive dynamics, and three-movement structure.
Step-by-step explanation:
Haydn, one of the great classical composers, wrote a total of 62 keyboard sonatas. His keyboard sonatas were known for their inventive melodies, expressive dynamics, and use of contrasting themes. They typically follow a three-movement structure, consisting of a fast first movement, a slower and more lyrical second movement, and a lively and energetic third movement.