String Quintet (Schubert) No. 3 in C major, K. 515 and Beethoven's String Quintet, Op. 29 in C major. According to Charles Rosen, the opening theme of Schubert's work emulates many characteristics of the Mozart quintet's opening theme, such as decorative turns, irregular phrase lengths, and rising staccato arpeggios (the latter appear only in Schubert's recapitulation). But whereas the string quintets of Mozart and Beethoven are composed for a string quartet augmented by a second viola, Schubert adopts a somewhat unconventional instrumentation, employing two cellos instead of two violas, creating richness in the lower register. Before Schubert, Luigi Boccherini had replaced the second
String Quintet (Schubert) viola with a second cello; however, Schubert's use of the second cello is very different from Boccherini's, who uses the additional cello to create an additional viola line. Alfred Einstein has proposed that Schubert's use of a second cello to enhance the lower strings may have been suggested by George Onslow, who used a double bass in some of his quintets. The string quintet consists of four movements in the usual quick-slow-scherzo-quick pattern: In common with other late Schubert works (notably, the symphony in C major, D. 944, the piano sonata in B-flat major, D. 960, and the string quartet