Piano Sonata No. 4 is a classical music composition written by Ludwig van Beethoven in 1796-1797. It is part of his early piano sonatas and is known for its lively character and innovative structure. The sonata consists of three movements: Allegro, Adagio, and Rondo, showcasing Beethoven's developing style and emotional depth. The first movement, Allegro, features a bright and energetic theme, while the second movement, Adagio, offers a contrasting lyrical and reflective quality. The final movement, Rondo, brings back the lively spirit, concluding the piece with a joyful and playful atmosphere.