Köchel catalogue son's earlier works; Mozart's catalogue of his own compositions (begun in February 1784 with K. 449) allows relatively precise dating of many of his later works. The catalogue included the opening bars of each piece, known as an incipit. Köchel divided the corpus into a main chronology of 626 works, and five appendices ("" in German, abbreviated to "Anh.") The appendices (Anh. I-V) included: Since Köchel published his original catalogue in 1863 (now referred to as K), the dating of Mozart's compositions has been subject to constant revision. Many more pieces have since been found, re-dated, re-attributed and re-numbered, requiring
Schubert opus/Deutsch number concordance Schubert opus/Deutsch number concordance Franz Schubert (31 January 1797 – 19 November 1828) was an Austrian composer. This is a concordance of those compositions by Schubert that were given opus numbers, and their corresponding Deutsch catalogue numbers. Only a small minority of Schubert's works were published in his lifetime. Not all published works were allocated opus numbers, and the sequence of opus numbers that were allocated bore little relationship to the order in which the works were either composed or published. For example, the first of his works to be published, the song "Die Forelle", was given the opus number