A number of new works by Mozart were discovered, while the new Köchel-Verzeichnis was in preparation.

The new Köchel offers the latest results of international Mozart research. This edition contains new entries in the main section from KV 627 for 95 works, mainly fragments and lost compositions by Mozart, which were missing in the previous editions or only mentioned in passing. It also provides an overview of Mozart’s arrangements of other works, cadenzas to his own and other works as well as studies, teaching material and all other musical notes in newly structured appendices. Corrections regarding information on misattributions have been made. Köchel returned to its original numbering system from 1862, and has indexed by a thematic overview, numerous indices, and an extensive bibliography.

Some of the works now published were already known to exist and so a place had been kept for them in earlier editions. This was the case, for example, with the aria “Per la ricuperata salute di Ofelia” KV 477a (also known as the “Freudenlied,” or “Song of Joy”), the aria “Die neugeborne Ros entzückt” KV 365a, and the keyboard piece KV 626b/16 (now KV Anh. A 66), that was trailed in 2021 as “Ninety-Four Seconds of New Mozart.”

This edition of the Köchel-Verzeichnis, compiled from scratch over decades of work by the publishing house Breitkopf & Härtel and the International Mozarteum Foundation, has been presented in Mozart’s home town of Salzburg. The new Köchel is now accessible in a print and digital format. The digital version is available in English.