The Piano Trio No. 4, op. 11, by Ludwig van Beethoven, is one of a series of early chamber works, many involving woodwind instruments because of their popularity and novelty at the time. The trio is scored for Piano, Clarinet (or violin), and Cello (sometimes substituted by bassoon). The trio is in the key of B flat major, probably to facilitate fast passages in the B flat clarinet, which had not yet benefited from the development of the Boehm System. It was composed in 1797, and published in Vienna the next year; Beethoven dedicated the piece to Countess Maria Wilhelmine von Thun.
The trio is in three movements:
Allegro con brio
Tema con variazioni (Pria ch'io l'impegno: Allegretto)