The fluid nature of music, especially in the realm of transcription from one medium to another, is on ready display in the output of such masters as Bach and Handel, who worked in a period when the rescoring and rearrangement of musical materials was not at all uncommon. We know that Bach reworked his solo violin music in works for lute, and he recycled some of that same music as a festive opening Sinfonia for his Cantata No. 29. Handel drew on music from his Concerti a due cori for the chorus “Lift up your heads” in the oratorio Messiah. His borrowings from other composers (often without credit) were not so scandalous in those days as they would be in our own time.

When Mozart, always in need of funds, set about securing subscribers for a set of three string quintets in 1788, he produced the third work by drawing on his back catalog. To supplement two new works (K. 515 in C major and K. 516 in G minor), Mozart adapted one of his greatest wind serenades, K. 388 in C minor, for the ensemble of two violins, two violas, and cello.

Despite its original designation as a serenade, the work (composed in 1782 and scored for pairs of oboes, clarinets, bassoons, and horns) was eminently suitable for such a reworking: It was structured in more symphonic form, with a stern and somber opening movement, a single slow movement, a remarkable minuet (about which more later), and a concise variations finale. (Compare that rundown with the expansive Serenade in B-flat major, known as the “Gran Partita,” K. 361; in addition to the opening, it has two slow movements, two minuets, a variations movement, AND a finale, a total of seven movements.)

The unison opening is typical of Mozart’s C-minor moodiness, and the entire opening movement maintains an atmosphere of intense seriousness. There is an element of resignation in the E-flat slow movement, which is followed by a canonic minuet (back in C minor), with the melodic material inverted in the trio. Repeated sections dominate the finale, which concludes with a C-major coda.

Admirers of the original wind version of the Serenade, rightly considered among the master’s greatest achievements in that arena, will miss virtually none of the actual musical material. Other than transferring the upper parts to violins and the middle voices to violas, Mozart has maintained the thematic and harmonic integrity of his music. Listening to the string quintet while following the wind octet score reveals no substantive structural changes. The actual scoring, of course, revealing the richness of Mozart’s understanding of each individual voice, explains why both versions have their merits and deserve our loyalty as Mozart-lovers.