Ludwig Ritter von Köchel since undergone revisions. Mozart's works are often referred to by their K-numbers ("cf." opus number); for example, the "Jupiter" symphony, "Symphony No. 41" K. 551. Moreover, Köchel arranged Mozart's works into twenty-four categories, which were used by Breitkopf & Härtel when they published the first complete edition of Mozart's works from 1877 to 1910, a venture partly funded by Köchel. He also catalogued the works of Johann Fux. Ludwig Ritter von Köchel Ludwig Alois Friedrich Ritter von Köchel (; 14 January 1800 – 3 June 1877) was an Austrian musicologist, writer, composer, botanist and publisher. He is best known for
Schubert Thematic Catalogue the 1951 edition, with updates derived from scholarship that had been published since 1951. From 1983 compact versions of the catalogue appeared, edited by Werner Aderhold and others. Changes to the numbering of Schubert's works were minor in these later editions. Schubert Thematic Catalogue Schubert: Thematic Catalogue of all his Works in Chronological Order, also known as the Deutsch catalogue, is a numbered list of all compositions by Franz Schubert compiled by Otto Erich Deutsch. Since its first publication in 1951, Deutsch (abbreviated as D or D.) numbers are used for the unique identification of Schubert's compositions. The Deutsch catalogue