The String Quintet No. 2 in C minor, K. 406/516b, was written by Wolfgang Amadeus Mozart in 1787. Like all of Mozart's string quintets, it is a "viola quintet" in that it is scored for string quartet and an extra viola (two violins, two violas and cello).[1] Unlike his other string quintets, however, the work was not originally written for strings. Having completed the two string quintets K. 515 and K. 516, Mozart created a third by arranging his Serenade No. 12 for Winds in C minor K. 388/384a, written in 1782 or 1783 as a string quintet. Although by then Mozart was entering each new work into his catalogue of compositions, he did not enter this quintet, perhaps because it was an arrangement rather than a new work.[2]
Since the wind serenade used pairs of oboes and clarinets, it was a straightforward matter to map these to the pairs of violins and violas. The arrangement is so successful that Richard Wigmore asserts, in his sleeve notes to the recording by the Nash Ensemble that "without prior knowledge few would guess that the work was not conceived for string quintet, even if the textures (except in the minuet) are generally simpler, less polyphonic than in K515 and 516".[3]