This new edition indicates that Mozart’s popular composition is a mature work dating from his time in Vienna, contrary to previous assumptions, and that the traditional ending does not correspond to the original version. The well-known closing bars, which have of course been included in this edition, were not in fact written by Mozart himself, but probably by August Eberhard Müller, who thereby shaped the piece to stand on its own. Mozart’s manuscript version however, as documented in the first edition, ends ten bars earlier on a dominant seventh chord, leaving the way open for further development and making it conceivable that the Fantasie was originally written as an introduction to a sonata in D major (to another of the late sonatas, K 576, in fact). With this information, the edition adds a totally new dimension to the performance of this widely known piece.