Piano Sonata No. 9, also known as the "Pathétique," is a classical piano composition by Ludwig van Beethoven. Completed in 1798, it is one of his most celebrated sonatas, showcasing his innovative style and emotional depth. The piece is structured in three movements: Grave – Allegro di molto e con brio, Adagio cantabile, and Rondo: Allegro. The sonata is notable for its dramatic contrasts and lyrical melodies. The first movement opens with a slow introduction, leading into a fast and energetic section. The second movement features a beautiful, flowing theme, while the final movement is lively and spirited, highlighting Beethoven's mastery of the piano.