The Köchel-Verzeichnis or Köchelverzeichnis is an inclusive, chronological catalogue of compositions by Wolfgang Amadeus Mozart, which was originally created by Ludwig von Köchel. It is abbreviated K. or KV. Köchel catalogue numbers not only reflect an ongoing attempt to establish a chronology of Mozart's works, but also provide a shorthand to refer to them. For example, Mozart's Requiem in D minor was, according to Köchel's counting, the 626th piece Mozart composed. Thus, the piece is designated K.626 or KV626. However, Köchel's original 1862 catalogue has been twice substantially revised, and some works have had three K. numbers assigned to them; e.g. Mozart's Horn Concerto No. 1, K.(412+514)/386b.
In the decades after Mozart's death there were several attempts to catalogue his compositions, for example by Franz Gleißner and Johann Anton André (published in 1833), but it was not until 1862 that Ludwig von Köchel succeeded in producing a comprehensive one. Köchel's 551-page catalogue was titled Chronologisch-thematisches Verzeichnis sämmtlicher Tonwerke W. A. Mozarts (Chronological-thematic Catalogue of the Complete Musical Works of W. A. Mozart). Köchel attempted to arrange the works in chronological order, but many compositions written before 1784 could only be estimated, although Leopold Mozart had compiled a partial list of his son's earlier works; Mozart's work book 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 (Anhang in German, abbreviated to Anh.) The appendices (Anh. I-V) included:
In the opinion of many the greatest of all composers, Wolfgang Amadeus Mozart (1756-1791) began his career as a child prodigy, and went on to achieve pre-eminence in every genre to which he turned his hand ... (The letter “K”, appended to Mozart’s music, refers to Ludwig von Köchel’s 1862 catalogue of his output) ... Facebook. Twitter. Pinterest ... .