Köchel catalogue 225: The New Complete Edition" contains premiere performances of previously lost compositions and never recorded fragments, as well as key works in alternative versions and recordings of legendary historic performances. Köchel catalogue The Köchel catalogue () is a chronological catalogue of compositions by Wolfgang Amadeus Mozart, originally created by Ludwig von Köchel, in which the entries are abbreviated "K." and "KV". The numbers of the Köchel catalogue reflect the continuing establishment of a complete chronology of Mozart's works, and provide a shorthand reference to the compositions. According to Köchel's counting, "Requiem in D minor" is the 626th piece Mozart composed,
Köchel catalogue three revised editions of the catalogue. Subsequent editions – especially the third edition (K) by Alfred Einstein (1937), and the sixth edition (K) by Franz Giegling, , and Alexander Weinmann (1964) – have reflected attempts to arrange the growing list of works in a more accurate chronological order, according to various levels of scholarship. A major shortcoming of K was that there was no room to expand the strictly sequential numbering in the main catalogue to allow for any new discoveries or further reassessment of existing works. For the 1937 edition (K) Einstein (following the analyses of Théodore de Wyzewa