Piano Sonata No. 26, also known as the "Largo Appassionato," is a composition by Ludwig van Beethoven. Completed in 1801, it is part of his early piano sonatas and is notable for its emotional depth and lyrical melodies. The sonata is structured in three movements, showcasing Beethoven's innovative approach to form and harmony. The first movement, marked "Allegro," features a lively theme, while the second movement, "Adagio," presents a contrasting, expressive character. The final movement, "Allegro," brings the piece to a spirited conclusion. This sonata reflects Beethoven's transition from classical to more romantic styles in his music.