The Neue Mozart-Ausgabe (abbreviated as "NMA"; in English, New Mozart Edition) is the second complete works edition of the music of Wolfgang Amadeus Mozart. A longer and more formal title for the edition is Wolfgang Amadeus Mozart. Neue Ausgabe sämtlicher Werke.
The main corpus of the edition was published between 1955 and 1991 by Bärenreiter-Verlag, consisting of the actual authentic music of Mozart along with a "Supplement"; the latter includes arrangements by Mozart of others' music and works whose authenticity has not been fully established. Still being published are the Critical Reports – technical commentaries in German. By 2008 these were nearly complete.
The Neue Mozart-Ausgabe is an advance over the previous complete works edition of Mozart published by Breitkopf & Härtel from 1877 to 1883 (with supplements until 1910), which is sometimes referred to today as the Alte Mozart-Ausgabe (or "Old Mozart Edition"). One of the editorial directors, , writes that "The NMA aims to be a historical-critical edition and to offer as such the latest state of philological-musicological procedure as well as practical knowledge (particularly with regard to performance) of Mozart's creative production."
Highly regarded and frequently used by performers of Mozart's music and musical scholars, the Neue Mozart-Ausgabe is an indispensable reference for anyone seriously interested in the output of this composer. H. C. Robbins Landon has called it "an absolute necessity if we are to perform Mozart correctly," and on one occasion had to insist that the Vienna Philharmonic use the NMA for a series of recordings of Mozart's symphonies rather than the less accurate Breitkopf & Härtel edition mentioned above.
At the same time, the NMA is not entirely free of problems, although to most observers these do not detract from the scholarly achievement that this edition clearly represents.
Stanley Sadie remarks that the work of the NMA was "hampered by the removal in World War II and the unavailability until 1980 of most of the largest single collection of Mozart autographs, that of the Berlin State Library, Berlin." Consequently, the editors of the NMA had to manage with this state of affairs as well as possible. In editing The Marriage of Figaro for the NMA, which appeared in 1973, Ludwig Finscher was only able to access the first two acts of the autograph score. In editing the Piano Concerto No. 27, K. 595, Wolfgang Rehm actually had to make use of a photographic reproduction of the autograph made before the war, which was provided by the pianist Rudolf Serkin, since the autograph itself was not accessible in 1960 when the NMA volume containing the concerto was published.