Following common practice at the time, in this work Beethoven incorporated variations on popular themes from opera, notably from Das rote Käppchen (literally translated as The Red Cap), a Singspiel by Carl Ditters von Dittersdorf, which had its premiere in Vienna in 1788. The opera reached Bonn in 1792, during the last months that Beethoven stayed there. Beethoven took one of the most popular pieces of this opera, a small segment of melody of Ja, ich muss mich von ihr scheiden (Yes, I must leave her), as the starting point for this trio. This line is from an aria sung by the village mayor Hans Christoph Nitsche, who is announces that he must leave his wife. Beethoven's variations were probably finished when he left Bonn – a short sketch from 1792 has survived – but were published as Op. 44 in 1804.
The theme is a series of simple unadorned arpeggios in octave unisons by all three players. Beethoven then develops fourteen variations, decorative in the tradition of the eighteenth century but with contrasting spirit and textures employed. The tenth variation, syncopated and vigorous, is followed by an almost exaggeratedly reserved dialogue while the twelfth variation's gentle ambling is interrupted by a burst of coarse fortissimo. This work includes two slow variations in E-flat minor (Nos 7 and 13). The final variation begins allegro in 6/8, dynamic and joyful, interrupted by a brief interlude marked andante. The conclusion is marked presto, led by the piano. (Wikipedia)