The Piano Sonata No. 9 in E major, Op. 14, No. 1, is an early-period work by Ludwig van Beethoven, dedicated to Baroness Josefa von Braun, one of his patrons at that time. It was composed in 1798 and arranged for string quartet by the composer in 1801, the result containing more quartet-like passagework and in the more comfortable key of F major.
Mae'r testun uchod ar gael o dan drwydded y CC BY-SA 3.0. Mae'n defnyddio deunydd o erthygl Wicipedia "Piano Sonata No. 9 (Beethoven)".