The Septet in E-flat major for clarinet, horn, bassoon, violin, viola, cello, and double bass, Op. 20, by Ludwig van Beethoven, was sketched out in 1799, completed, and first performed in 1800 and published in 1802. The score contains the notation: "Der Kaiserin Maria Theresia gewidmet" (Dedicated to the Empress Maria Theresa). It was one of Beethoven’s most popular works during his lifetime. Structure and analysis The composition is in six movements and runs approximately 40 minutes in performance: Analysis The overall layout resembles a serenade and is in fact more or less the same as that of Mozart's string trio, K. 563, in the same key, but Beethoven expands the form by the addition of substantial introductions to the first and last movements and by changing the second minuet to a scherzo. The main theme of the third movement had already been used in Beethoven's Piano Sonata No. 20 (Op. 49 No. 2), which was an earlier work despite its higher opus number. The finale features a violin cadenza. The scoring of the Septet for a single clarinet, horn and bassoon (rather than for pairs of these wind instruments) was innovative. So was the unusually prominent role of the clarinet, as important as the violin. The Septet was one of Beethoven's most successful and popular works and circulated in many editions and arrangements for different forces. In about 1803, Beethoven himself arranged the work as a trio for clarinet (or violin), cello, and piano, and this version was published as his Op. 38 in 1805 in Vienna. Beethoven dedicated the Trio Op. 38 to Professor Johann Adam Schmidt (1759–1809), a German-Austrian surgeon and ophthalmologist, and a personal physician of Beethoven, whom he attended to from 1801 until 1809. Conductor Arturo Toscanini rearranged the string section of the Septet so that it could be played by the full string section of the orchestra, but he did not change the rest of the scoring. He recorded the Septet for RCA Victor with the NBC Symphony Orchestra on November 26, 1951, in Carnegie Hall. Influence Franz Schubert composed his 1824 Octet (in F major, D. 803) for the clarinetist Ferdinand Troyer who had requested a piece similar to Beethoven's Septet, and the works accordingly resemble each other in many ways. In 1840, Franz Liszt arranged Beethoven's Septet for piano, first for two hands (S.465) and then for four hands (S.634). Several other