Among the piano sonatas by Joseph Haydn, the Sonata in E flat Hob. XVI:49 is probably the piece we know most about in terms of genesis. It is one of the few sonatas that have survived in Haydn's own handwriting, and the correspondence between Haydn and his 18 years younger admirer Marianne von Genzinger refers to the work several times. That alone was reason enough for Christa Landon, the renowned editor of Haydn's piano sonatas in the Wiener Urtext Edition, to present an edition of this work with a facsimile of Haydn's autograph many years ago. The new edition now publishes the facsimile with the musical text newly revised by Ulrich Leisinger.