In some ways, Beethoven's "Kreutzer" Sonata is the violin sonata, the great hit of the genre. Which only makes attempts to define the genre all the harder, since it is a fiercely original work that remade not only the violin sonata but duo sonatas generally.

Composed in 1803, it is one of the works marking the beginning of Beethoven's middle period of boldly heroic work. There was a new violinist in Vienna that spring, and Beethoven's patron Count Lichnowsky put the two musicians together. Born in Poland as the son of a West Indian father and a European mother, Bridgetower made his debut in Paris at the age of ten. He and his father then moved to England, where he became a celebrity prodigy, promoted as the "son of the African Prince."

In 1802 Bridgetower had gone to visit his mother in Dresden and his success there produced letters of introduction to Lichnowsky and others in Vienna. He and Beethoven quickly became friends, and planned a concert together in May 1803. Beethoven already had the finale for a violin sonata in hand, one he had composed for his Op. 30, No. 1 Sonata but replaced. He had been sketching two other movements, which he proceeded to finish in great haste - Bridgetower ended up reading the second movement from the composer's manuscript during the performance, there having been no time to copy out the violin part.

Beethoven well understood how different this new sonata was from any that had come before, including his own eight. His title page describes it as a "Sonata for the pianoforte and violin obbligato, written in a very concertato style, almost like a concerto" - in other words, nothing like the modest sonatas for keyboard with optional violin accompaniment of Mozart's youth.

The Sonata begins with a slow introduction, something expected more in a symphony than a violin sonata, and the violin has the first notes, echoed by the piano. This chromatic introduction emphasizes the key of D minor, making it harmonically a bookend matching the coda of the finale. The main Presto is a vigorously driven - although also often interrupted - dialog in A minor, whose passionate intensity later inspired Leo Tolstoy's short story, "The Kreutzer Sonata," which in turn was the impetus for Janácek's String Quartet No. 1.

The second movement is an expansive theme with four variations and a coda, rhythmically and harmonically off-kilter. It is in F major, an odd key for a piece in A major but one related to the prominent D-minor digressions in the framing movements. Not only that, the theme begins not in F, but with four bars on the dominant. With the variations, Beethoven follows a pattern much like Mozart's letting the piano dominate the first variation and the violin the second, and putting his next-to-last variation in minor mode.

The spryly sprung finale, the only movement actually in A major, is in sonata form, though with its own odd metrical deviation near the end of the exposition, mirrored, of course, in the recapitulation.

Shortly after the concert, Beethoven and Bridgetower quarreled over a woman (according to Bridgetower's recollection years after Beethoven had died). Bridgetower returned to England (eventually taking a music degree from Cambridge) and Beethoven dedicated this startling new work to the French violinist Rodolphe Kreutzer, who found it completely baffling and never performed it.

- John Henken is Director of Publications for the Los Angeles Philharmonic Association.

12/06