Ludwig van Beethoven's Piano Sonata No. 28 in A major, Op. 101, was written in 1816 and was dedicated to the pianist Baroness Dorothea Ertmann, née Graumen. This sonata marks the beginning of what is generally regarded as Beethoven's final period, where the forms are more complex, ideas more wide-ranging, textures more polyphonic, and the treatment of the themes and motifs even more sophisticated than before. Op. 101 well exemplified this new style, and Beethoven exploits the newly expanded keyboard compass of the day.
This piano sonata consists of four movements:
As with the previous sonata, it is unclear why Beethoven wrote Op. 101. The earliest known sketches are on leaves that once formed the parts of the Scheide Sketchbook of 1815–16. It shows the first movement already well developed and notated as an extended draft in score, and there are also a few preliminary ideas for the final Allegro.
Beethoven himself described this sonata, composed in the town of Baden, just south of Vienna, during the summer of 1816, as "a series of impressions and reveries." The more intimate nature of the late sonatas probably has some connection with his deafness, which by this stage was almost total, isolating him from society so completely that his only means of communicating with friends and visitors was by means of a notebook.
Beethoven offered the sonata for publication in a letter to Breitkopf and Härtel on July 19, 1816, when it was still far from complete. Eventually it was sold to the local Viennese publisher Sigmond Anton Steiner, after its completion. It was published in January 1817, and would appear in public the following month after delays.
The Piano Sonata No. 28, Op. 101 is the first of the series of Beethoven's "Late Period" sonatas (although sometimes Op. 90 is considered the first), when his music moved in a new direction toward a more personal, more intimate, sometimes even an introspective, realm of freedom and fantasy. In this period he had achieved a complete mastery of form, texture and tonality and was subverting the very conventions he had mastered to create works of remarkable profundity and beauty. It is also characteristic of these late works to incorporate contrapuntal techniques (e.g. canon and fugue) into the sonata form.