For more than 200 years Mozart’s piano sonatas have been part of every pianist’s repertoire. Research done over the last few decades has made it possible, however, to establish more accurate dating and ordering of these works. Expert examination of original documents has shown that many printed editions from the eighteenth Century give more reliable detail than Mozart’s own written scores; many of these works were prepared for publication by the composer himself and marked with precise indications for performance with regard to ornamentation, dynamics and articulation. All this, together with the rediscovery of documents that only became accessible again at the end of the 20th Century, gives reason enough to justify the publication of a new Wiener Urtext edition of Mozart’s Piano Sonatas.To follow the second volume, published in the spring of 2003 with Sonatas K 330 to K 576, we now present the first volume, which contains the Sonatas K 279 to K 311. For Sonata K 284, variation XI in the final movement is given both in the version that appears in the original manuscript and in the version used in the first edition; in order to make the music easier to read, both versions are given in normal print size. Music that is clear and well laid out, with page turns in convenient places, makes this edition extremely user-friendly.Advice on performance by the renowned Mozart specialist Robert D. Levin provides fresh stimulus for what can otherwise too often become a rather tired interpretation.