This sonata has an unusual large-scale form: its first two movements are in fact combined, beginning with an Adagio and then transitioning into a more typical first-movement Allegro. The opening is too extensive to simply be a slow introduction, but not quite enough to be a full movement on its own (besides, how unusual to start with a slow movement). Then immediately after these glommed-together movements, the sonata leaves behind its minor key and switches to bright G major for the toe- tapping finale. Only the other Op. 5 cello sonata, No. 1 in F Major, has a similar shape. These sonatas are brothers, two of a kind.
It so happens that Beethoven was actually working with a pair of brothers at the time: the cellists Jean-Louis Duport and Jean-Pierre Duport, both of whom served Friedrich Wilhelm II, the king of Prussia, at his Berlin court. The king himself was a skilled amateur cellist—so when Beethoven visited Berlin on tour in spring 1796, he found himself surrounded by cellists. There was relatively little solo repertoire for the instrument at the time (Bach’s suites were mostly forgotten before later revival), so Beethoven set to work, inspired by the Duport brothers and their patron king. Jean-Louis, the younger brother, premiered the sonata in Berlin with Beethoven at the keys, and both Op. 5 sonatas were dedicated to Friedrich Wilhelm II. Beethoven apparently declined an offer to stay in Berlin in employment of the king, but was rewarded for the sonatas with a gold snuffbox filled with gold coins—the 18th- century version of slipping a performer their check after the concert.
The sonata explores all the different sides of the cello, using it as a lyrical tenor voice, a reinforcing bass line, a punctuating mark against the piano, and as a textural element (those rapid broken chords in the finale). Beethoven also gave himself a prominent piano part—in fact putting the piano first in the title—reminding us that at this time in his life, at 25 years old, he was as much a touring performer as he was a composer.