The Sonata in E-flat major No. 49 is one of Haydn's most popular piano sonatas ever. He dedicated it to Anna Jerlischek, in charge of the Esterházy household, who had commissioned it. However, Haydn had apparently been working on the work for some time when he received this commission and originally had another dedicatee in mind, Maria Anna von Genzinger, the wife of the Viennese personal physician of Nicholas I Esterházy.

In the P.S. of a letter to her, he wrote: "N.B.: Mademoiselle Nanette [Anna Jerlischek] must know nothing of the fact that this Sonata was already half completed, for otherwise she might get the wrong impression of me, and this might be very disadvantageous for me, since I must be very careful not to lose her favour.”

The secret dedicatee evidently feared technical difficulties in crossing with the left over the right hand in the Adagio of the sonata and wrote to Haydn: "I like the Sonata very much, but there is one thing which I wish could be changed (if by so doing it does not detract from the beauty of the piece), and that is the passage in the second part of the Adagio, where the hands cross over; I am not used to this and thus find it hard to do, and so please let me know how this could be altered." Haydn, however, left this pianistically effective section unchanged.

This single edition has been released as part of a series of popular works from Bärenreiter's catalogue in celebration of the 100th anniversary of the publishing house. It constitutes an excerpt from the anthology of Haydn's "Late Piano Sonatas" (BA10804), edited by Bernhard Moosbauer and Holger M. Stüwe with notes on historical performance practice and fingerings by Rebecca Maurer .