The five consecutively numbered sonatas on this afternoon’s program span the years 1809 to 1816, when Beethoven was transitioning from the “heroic” idiom of his middle period to the more introspective, convoluted language of his later works. He had special affection for his Piano Sonata No. 24 in F-sharp Major, written in the wake of the mighty “Emperor” Piano Concerto. Commissioned by the London-based publisher and pianist Muzio Clementi, the two-movement work is notable for its tonality—unique in Beethoven’s oeuvre—as well as its concision and dynamic energy. It was published in 1810 in tandem with the equally concise Piano Sonata in G Major.

The programmatic Piano Sonata in E-flat Major commemorates the departure from Vienna (and subsequent return) of Beethoven’s benefactor Archduke Rudolph during the Napoleonic Wars; the three movements are titled “The Farewell,” “Absence,” and “The Reunion.” Beethoven waited some five years to write his next work in the genre, the dramatic and highly compressed E-Minor Piano Sonata of 1814, and an additional two years separated it from its similarly unconventional sequel. Many aspects of the A-Major Piano Sonata—from the tonal and metrical ambiguity of the first movement, which Wagner considered a prime specimen of “endless melody,” to the profusion of canonic and fugal writing—foreshadow the dense, knotty idiom of Beethoven’s late-period works.