One of the movements of this sonata is a scherzo. Beethoven is the creator of this style of movement. It is much less formal than the minuet which Haydn introduced into the sonata. This especial scherzo has a trio which in the broad sweep of its arpeggios is as modern sounding as anything Beethoven wrote for the pianoforte.
There are other sonatas by Beethoven that indicate efforts on his part to be less trammeled by considerations of form. Regard as an example the "Sonata Quasi Una Fantasia," Opus 27, No. 2, generally, and by no means inaptly, called the "Moonlight Sonata." This begins with the broad and beautiful slow movement, with its sustained melody, a poem of profound pathos in musical accents. It is followed by an Allegretto, "_une fleur entre deux abîmes_" (a flower 'twixt two abysses) Liszt called it; and then comes the concluding movement, a Presto agitato, which is one of Beethoven's most impassioned creations. There are only three movements, and the usual sequence is inverted, for the last of the three is the Sonata movement. At the end of the Adagio sostenuto and at the end of the Allegretto as well, is the direction "_attacca subito il sequente_," indicating that the following movement is to be attacked at once and denoting an inner relationship, a psychological connection between the three movements. Throughout the work the themes are of extraordinary beauty and expressiveness even for a Beethoven and the whole is a genuine drama of human life and experience. This impression is produced not only by the very evident psychological connection between the movements, but by the manner in which the composer holds on to his themes, developing them through bar after bar as if he himself appreciated their beauty and were reluctant to let go of them and introduce new material. The entire first movement, practically a song without words of the most exquisite poignancy, is built on a single motive with a brief episode which is more like an improvisation than a set part of a movement; while the last movement consists of four eloquent themes with only the merest suggestion of connecting episodes. The working out in the last movement is almost wholly a persistent iteration of the second theme. This persistent dwelling upon theme and the psychological relation between the different movements make this "Moonlight Sonata" to me the most modern sounding of Beethoven's pianoforte works, although when mere structural greatness is considered, most critics will incline to rank it lower than the "Sonata Appassionata" and the four last sonatas, Op. 106 and 109-11. Undoubtedly, however, it is the most "temperamental" of his sonatas--and herein again the most modern. My one quarrel with Von Bülow is that he made it so popular by his frequent playing of it and his exceptionally poetic interpretation of it, that the great virtuosos shun it, very much as they shun the sixth Chopin waltz (Mme. Dudevant's dog chasing its own tail), because it is played by every pianoforte pupil of every girls' boarding school everywhere.