Simple means, employed to glorious effect, resulted in this extraordinary work from the pen of a 31-year-old genius who would be dead at the age of 35. He had composed his last three symphonies (No. 39 in the same key, E-flat; No. 40 in G minor; and No. 41 in C major, the “Jupiter”) in the three months prior, but his depressed circumstances would preclude any further composition for some nine months.

In his earlier years, Mozart had produced a wide assortment of works with such interchangeable titles as Cassation, Notturno, Serenade, and Divertimento, some scored for wind ensemble, some for strings, some for orchestra, including charming but insignificant works as well as celebrated gems such as the Gran Partita for Winds, Eine kleine Nachtmusik, and the “Posthorn” Serenade.

In the more serious chamber music genres, Mozart had composed an extended collection of works for string quartet, and he wrote a masterful series of string quintets, but the Divertimento was his first and only music for string trio. Mingling the intimacy of forces with an abundance of invention, he produced his longest chamber work, and yet avoided any potential tedium by varying the tempos and the formal structures of the six movements.

The composer was in dire financial straits in 1788, and he wrote (not for the first time) to his fellow Freemason Michael Puchberg asking for a loan; by way of repayment, Mozart dedicated the Divertimento, K. 563, to Puchberg. Despite its modest instrumentation, the work received its premiere at a public concert, April 13, 1789, in Dresden. Mozart himself played his favorite instrument, the viola.

The sequence of movements was typical for such a “diverting” work, with an opening fast movement matched by a similar one to conclude, and a pair of slow movements plus two minuets sandwiched in between. In addition to the richness of his thematic materials, Mozart was clever enough to diversify his musical methods, writing one slow movement in sonata form, the other as a theme and variations. His minuets also exhibited differing structures, including an extra trio section for one of them. Analysis of such a masterpiece would be superfluous.

Dennis Bade is Associate Director of Publications for the Los Angeles Philharmonic.