Alfred Brendel, piano By the late 1780s, Haydn's works for keyboard were clearly intended for the piano as opposed to the harpsichord. His exploitation of the dynamic potential of the relatively new piano grows with each of his last sonatas. Until Beethoven's middle-period sonatas, Classical-era works for solo keyboard were very often written for a composer's students and were intended to stress certain aspects of technique. At the time, the concerto was the vehicle for the performing virtuoso. Haydn was never a keyboard virtuoso, but had a number of students for whom he composed piano sonatas. The wide range of ability among his students accounts for the disparate levels of sophistication and technical difficulty we find among the surviving sonatas, most of which were written before 1770. Some of these works have been lost because Haydn gave the manuscripts to his students without making copies. A few of Haydn's sonatas, however, were not composed for his students. The Sonata in E flat major, H. 16:49, was composed for Marianne von Genzinger, the wife of the Esterházy family physician. Haydn's relationship with Genzinger may have grown from a mutual affinity for things musical, but it seems certain from some the composer's letters that the relationship grew into some version of love. However, most of the composer's communications to Genzinger, although in a more relaxed style than those to others, are discreet, often discussing musical issues. Concerning the E flat sonata, Haydn referred to the second movement, an Adagio, as "quite new...it contains many things I shall analyze for Your Grace when the time comes; it is rather difficult but full of feeling." The E flat major sonata is also a fairly late work, completed in 1790. It shares a certain intimate style with other works directed toward Genzinger, but is quite Beethovenian in some respects. (In general, Haydn's late keyboard sonatas are among his most forward-looking works, and perhaps those in which his influence upon Beethoven is most visible.) The first movement, in sonata form, is marked Allegro non troppo and moves forward quickly in a bouncing triple meter. Compared to those of the symphonies Haydn composed during this same period, the transition between key areas is brief. We hear a plethora of material on the secondary key, B flat major, most of which shows up in the extensive development. In the recapitulation, the transition, as usual, resolves the secondary material to the tonic. A coda develops transitional material on its way to a firm close—a procedure Beethoven would borrow from Haydn and expand upon. The exquisite Adagio cantabile is an ABA structure in B flat major with highly decorated thematic material. Touches of the tonic minor add a melancholic feel to the movement, while numerous runs suggest that Genzinger had a formidable technique. Haydn composed a large Minuet with two Trio sections as the finale of the E flat major sonata. Everything begins conventionally enough: the Minuet follows the traditional pattern of repetition, with the first part consisting of an eight-measure phrase that closes on the dominant. The first Trio opens with a theme built of descending scales, which contrast with the rising figures of the second part. After the Trio we hear a literal return to the Minuet, as we expect, but only the first part appears and it turns out to be a bridge to the second Trio, in E flat minor. This in turn is followed by a slightly varied reprise of the entire first Minuet section in E flat major.