Mozart’s sonatas are possibly most comparable to those of Haydn, which is not unexpected, given that Mozart was lucky enough to have been taken under Haydn’s wing, so to speak. Although, it is unlikely that Mozart’s earlier sonatas are very much shaped by Haydn’s, as Mozart was probably unaware of Haydn’s sonatas at the time. Despite this, there is a ‘use of the classical language,’ that is, ‘undoubtedly similar,’ such as in the comparable slower movements from Mozart’s K 280, and Haydn’s Hob. XVI: 23. However, it is much more plausible that Mozart’s later works were more likely to have received influence from Haydn, so it is important to consider Haydn when looking at how Mozart’s compositional style developed over the years. For example, earlier sonatas by Mozart almost indefinitely stuck to the standard three movement idea, often in an alternation between allegro, adagio and allegro, or fast, slow, fast, whereas Haydn would in fact frequently use only two movements.
Minuets were also a deviation included in many of Haydn’s sonatas, but only a few of Mozart’s use them in composition, such as K282. It is difficult to know whether this is Mozart deliberately trying to learn from Haydn by infusing his ideas, or whether this is simply Mozart experimenting with new compositional ideas. Whatever the case, it is only fair to say that whatever influences Mozart did take from other composers, he still thoroughly infused all of his works with his own unique style and embellishments. For example, Haydn would typically use monothematic expositions, with identical beginnings for two subjects, whereas Mozart’s expositions could be described as ‘richly polyphonic.’ It is evident that both composers place significant emphasis upon transitions within the first movements of their expositions, yet there are still some very ‘marked differences,’ which draw them apart as successful composers. In their own right, Mozart would more often modulate to one degree sharper than the tonic key, while Haydn was more interested in establishing the dominant key.
Overall, I think that Mozart’s sonatas will continue to receive the respect that they deserve; his sonatas vary so much stylistically that they are always able to offer something new to both the musician and the listener. It is interesting to see Mozart playing with the standards of the genre, by altering the lengths of the expositions for example, and defying the ‘rules’ for what key the piece should move to next. As such, his works have a sense of unpredictability, which makes them more interesting to listen to. That said, there is not the sense of fragmentation there that could be said of some of Haydn’s among others’ works. Mozart manages to maintain a beautiful sense of fluidity throughout all of his sonatas, even when they are composed to teach his students. To do this, he uses both traditional techniques, such as the Alberti bass, but also he alters chordal progressions to fit with the circle of fifths, for example, to create naturally flowing pieces. The fact that there are so many different styles and influences in his works, makes Mozart’s sonatas all the more fascinating. It is impossible to know what ideas he has taken from whom, and what are entirely his own creations. This fusing of ideas combined with Mozart’s innovation, has left us with some of the most cleverly crafted pieces in history, and all should be viewed us such; we should not be dismissing some of the more deceptively simple sonatas such as K 545, as all of them have something to offer.