The C major Quintet, composed in 1801, and like the op. 23 and op. 24 violin sonatas dedicated to Count von Fries, has remained something of an outsider in Beethoven's chamber music, considered ‘important’ by most writers, but not often played. Robert Simpson regards its neglect as ‘shameful’, claiming, perhaps provocatively, that it ‘could be in some ways regarded as a crown to op. 18’, praising in particular its ‘breadth and economy of line’, and adding that ‘fine works for this medium are not so plentiful that chamber players can afford to ignore it as often as they do.’ Other writers suggest that its importance lies in reflecting Beethoven's current interest in melody, and pass on without much further comment. Although Beethoven's recent studies with Salieri had broadened his approach to lyricism, melody, however defined, had already played an important part in the music he was composing in the late 1790s, and would continue to do so throughout his life.

The Quintet got off to a shaky start. Beethoven sold it to Breitkopf & Härtel as soon as the agreed six-month period during which Count von Fries had sole rights to it had expired, only to discover that Artaria had somehow got hold of the parts and planned to publish it without permission. A furious correspondence ensued, and the matter was resolved only after a court hearing. Happily, Count von Fries carried on with his support of Beethoven in the years that followed – he later became the dedicatee of the Seventh Symphony – and both Breitkopf & Härtel and Artaria continued to publish his music.

Beethoven's other string quintets

Apart from op. 29, Beethoven seems not to have warmed to the string quintet as a genre, though he toyed with it from time to time during his later years; indeed, he was working on one at the time of his death. He wrote the eighty-three-bar Fugue in D major for string quintet, op. 137, in a few hours on 28 November 1817, as a personal gift to Tobias Haslinger, who was planning to publish a complete edition of his music. He was increasingly absorbed in polyphonic studies at the time, and op. 137 is a poised and spritely study in five-part counterpoint, though not, of course, a quintet in the classical sense. Beethoven's other two quintets are arrangements.