Piano Sonata in B-flat major, K. 498a

The Piano Sonata in B-flat major, K. 498a (Anh.

It was first printed in 1798 by P. J. Thonus in Leipzig on behalf of Breitkopf & Härtel and attributed to Wolfgang Amadeus Mozart; an edition printed in c. 1805 already credited it as opus 26 of the Thomascantor August Eberhard Müller (1767–1817).

[1] Some publications still attribute it to Mozart, often as Piano Sonata No.

The movements are: The musicologist Alfred Einstein suggested that the Menuetto from this work might be a piano arrangement of the "missing movement" of Mozart's Eine kleine Nachtmusik, K. 525 (1787).

[3] The Andante is an arrangement of the variations movement of the concerto K. 450 in B-flat major, and the Rondo incorporates arrangements of passages from the finales of the B-flat concerti K. 450, K. 456, and K. 595.