Anton (or Antonio) Diabelli (5 September 17818 April 1858) was an Austrian music publisher, editor and composer. Best known in his time as a publisher, he is most familiar today as the composer of the waltz on which Ludwig van Beethoven wrote his set of thirty-three Diabelli Variations. Early life Diabelli was born in Mattsee near Salzburg, then in the Archbishopric of Salzburg. A musical child, he sang in the boys' choir at Salzburg Cathedral where he is believed to have taken music lessons with Michael Haydn. By the age of 19 Diabelli had already composed several important compositions including six masses. Diabelli was trained to enter the priesthood and in 1800 joined the monastery at Raitenhaslach, Bavaria. He remained there until 1803, when Bavaria closed all its monasteries. Career In 1803 Diabelli moved to Vienna and began teaching piano and guitar and found work as a proofreader for a music publisher. During this period he learned the music publishing business while continuing to compose. In 1809 he composed his comic opera, Adam in der Klemme. In 1817 he started a music publishing business and in 1818 he formed a partnership with Pietro Cappi to create the music publishing firm of Cappi & Diabelli. Cappi & Diabelli became well known by arranging popular pieces so they could be played by amateurs at home. A master of promotion, Diabelli selected widely-accessible music such as famous opera tune arrangements, dance music and popular new comic theatre songs. The firm soon established a reputation in more serious music circles by championing the works of Franz Schubert. Diabelli recognized the composer's potential and became the first to publish Schubert's work with "Erlkönig" in 1821. Diabelli's firm continued to publish Schubert's work until 1823 when an argument between Cappi and Schubert terminated their business. The following year Diabelli and Cappi parted ways, Diabelli launching a new publishing house, Diabelli & Co., in 1824. Following Schubert's early death in 1828 Diabelli purchased a large portion of the composer's massive musical estate from Schubert's brother Ferdinand. As Schubert had hundreds of unpublished works, Diabelli's firm was able to publish "new" Schubert works for more than 30 years after the composer's death. Diabelli's publishing house expanded throughout his life, before he retired in 1851, leaving it under the control of Carl Anton Spina. When Diabelli died in 1858 Spina continued to run the firm and published much music