The Köchel-Verzeichnis is a complete, chronological catalogue of compositions by Wolfgang Amadeus Mozart(1756–91) which was originally created by Ludwig von Köchel. It is abbreviated K. or KV. For example, Mozart’sRequiem in D minor was, according to Köchel’s counting, the 626th piece Mozart composed. Thus, the piece is designated K. 626 or KV 626. Köchel catalogue numbers not only attempt to establish chronology, but also give a helpful shorthand to refer to Mozart’s works.
In the decades after Mozart’s death there were several attempts to catalogue his compositions, but it was not until 1862 that Ludwig von Köchel succeeded. Köchel’s 551-page catalogue was titled Chronologisch-thematisches Verzeichnis sämmtlicher Tonwerke W. A. Mozart’s (Chronological-thematic Catalogue of the Complete Musical Works of W. A. Mozart). The catalogue included the opening bars of each piece, known as an incipit.
Köchel attempted arranging the works in chronological order, but the compositions written before 1784 could only be estimated. Since Köchel’s work, many more pieces have been found, re-attributed, and re-dated, requiring three catalogue revisions. These revisions, especially the third edition by Alfred Einstein (1937), and the sixth edition byFranz Giegling, Gerd Sievers, and Alexander Weinmann (1964), incorporated many corrections.