Composed: 1939

Length: 27 minutes

Orchestration: String orchestra (subdivided into soloists for each string instrument) requiring at least 6 first violins, 6 second violins, 4 violas, 4 cellos, and 2 double basses

Bartók's six string quartets, spanning his career from 1908 to 1939, are generally regarded as the 20th century's unsurpassed addition to the medium. They call to mind the far-reaching world of Beethoven's late quartets. And with Beethoven they share the paradox of presenting an uncompromising seriousness that nevertheless wields an immediate power to communicate.

The quartets provide an intimate entrée into the world of this withdrawn, sickly, enigmatic composer. But another light is shed by the delightful and brilliantly deployed string writing of his Divertimento. Bartók wrote the piece in an uncharacteristic dash of speed (in just two weeks in the summer of 1939) during an idyllic retreat in a cottage nestled in the Swiss Alps, a get-away provided by a discerning patron of the composer.

Such creative tranquility was of course an illusory respite, occurring as it did mere weeks before the onset of war and the events that would force Bartók to leave fascist Europe for the life of an exile in New York City. Immediately after the Divertimento, he launched into the profoundly grief-stricken expression of his sixth and final quartet.

So the Divertimento holds a place apart during a very grim time for the composer, its seemingly light-hearted, neoclassical title a kind of backward glance to music's acknowledged role as a source of civilized social entertainment, not always meant to bear the burden of intensely personal confessionalism. And the piece indeed finds Bartók in a relatively relaxed mood of congeniality.

That nod to the past extends into the Divertimento's very texture. Its three movements formally evoke an old-fashioned concerto grosso from the baroque (itself a forerunner of Mozart's style in the Sinfonia Concertante, which also hearkens to past models). The hallmark of the concerto grosso is the alternation between the full body of the ensemble and smaller collectives of solo players. Bartók relicates such effects with an evident pleasure in the sonic variety he is able to wrest by setting solo string sounds against each other and against the tutti effect of the whole string orchestra: through phrasing echoes, sudden dynamic contrasts, unexpected rhythmic accents, and dramatic shifts of harmonic gear.

Unlike some of his contemporaries, Bartók wasn't interested in grandiose theorizing about how to solve the musical crises of early modernism. Instead, he used his research into the provincial folks musics of Eastern Europe to forge a language liberated from tonal and metrical conventions. The result was music with an unavoidably visceral appeal. You can hear this in the very first measures thanks to the aggressive energy of Bartók's accented rhythms and the earthy modalism of his melodic ideas (which, following the insistent E-flat of the Haydn and Mozart, will be particularly apparent). But set against the vigor of his statements is a playful strategy pitting the solo against collective sonorities with an admirable diversity of invention.

The Adagio, with its muted, sotto voce strings, spidery chromatic steps, and stabbing outcries, summons the darker world of the Quartets - especially their surreal "night music." In the center of the movement, Bartók avails himself of one of his signature, long-pending crescendos to magnificent effect.

That disturbing atmosphere however is readily dispelled in the exultant rusticism of the rondo finale, its propulsive rhythms ingeniously parlayed into duple meter. Bartók's string quartet scores are crowded with special effects that test the limits of the string idiom, and here he revels in the paces through which he can put the basic call-and-response gesture of the concerto grosso style, with moments that sound like Handel being coerced into a gypsy dance. In the final pages, Bartók heats up the speed into a forward chase that holds a final set of surprises in store.

-- Thomas May is a senior editor at Amazon.com and a regular contributor to andante.com.