The year 1784 marks a decisive break in the evolution of Mozart’s piano concertos. Not only was it his most productive year, with six new compositions, but he also raised the genre to new technical and artistic heights previously reached only by his wholly unique early Concerto in E_b major, K. 271. Mozart, in his autograph thematic catalogue, assigned the Piano Concerto in G major, K. 453, to the 12th of April. It thus came a mere three weeks after he had completed its predecessor in D major, K. 451, from which it stands out with its more intimate inflection. Mozart also added refinements to the compositional fabric, the interweaving of soloist and orchestra, and achieved a surprising degree of formal license, especially in the second movement and in the final set of variations, which is crowned by an ending worthy of an opera buffa finale. Unlike most of his piano concertos – his most effective instrumental-genre in public performance – he did not write K. 453 for his own use but for his pupil Barbara (Babette) von Ployer, who had already been the recipient of the E_b-major Concerto K. 449. It was Mlle. Ployer who gave the work its première on 13 June of that same year 1784, at a concert organized by her father in Döbling.
K. 453 was one of Mozart’s few piano concertos to appear in print during his lifetime. In 1787 it was published in a set of parts by Bossler of Speyer as Opus 9. Yet it had already been accessible to the public before then. In 1785 it was offered for sale by the copying house of Lausch in Vienna, and was thus already in circulation. In this respect it differs from the concertos Mozart wrote for his own use, which he usually held back in order to market them elsewhere at a maximum profit. Given the absence of engraver’s copies, proofsheets, and relevant correspondence, it cannot be claimed for certain that Mozart had any part in the Bossler print, which abounds in mistakes, but it is fairly safe to assume that he did not. He probably did not meet Bossler until the autumn of 1791, when the publisher gave a concert in Vienna with Marianne Kirchgessner. In 1793 André in Offenbach issued a reprint of the work, albeit not absolutely identical, as Opus 15. However, André did not edit this set of parts from the autograph score, which he only acquired from Constanze Mozart, along with other manuscripts, in 1799. (This is evident from the absence of the words “Ausgabe nach der Original-Handschrift” [edition based on the original manuscript] that André added to the title pages of every work he prepared from Mozart’s autographs.) Thus neither of these editions is of any value as a source. The same can also be said of the contemporary sets of handwritten parts from the abbeys of Melk and Kroměříž. The first reliable edition of K. 453 was the full score prepared from the autograph by André in 1852.
Since the publication of this work in the Neue Mozart-Ausgabe (NMA), the source situation has been fundamentally changed by the rediscovery of the autograph score, preserved today in the Biblioteka Jagiellońska, Kraków. This score had been missing since the end of the Second World War, and the NMA editors were forced to make do with the Eulenberg pocket score, a print prepared from the autograph by Friedrich Blume before the war, as their principal source. However, Blume’s editorial notes were limited to a few comments in his preface, not all of which are verifiable when compared to the autograph.
The editor wishes to thank those libraries, especially the Biblioteka Jagiellońska, Kraków that kindly placed source material at his disposal and provided useful information.

Munich, Fall 2008