Ludwig van Beethoven composed 32 pieces of music known as sonatas. These sonatas are considered some of the most influential works in the history of classical music. Beethoven's sonatas span a variety of musical styles, from the early Classical period to the Romantic era. They are often divided into three periods: early, middle, and late. The early sonatas are characterized by their simplicity and clarity, while the middle sonatas are more complex and expressive. The late sonatas are considered some of Beethoven's greatest works, and are known for their emotional intensity and technical difficulty.