About this work
The String Quartet in B flat major (K. 172) is one of a series of six quartets Mozart composed in the late summer and early fall of 1773, probably in Vienna, a few months after returning from a tour of Italy. While the set of quartets composed near the end of his travels (K. 155-160) clearly exhibited the young composer's absorption of the musical styles and forms encountered during his Italian tour, the set of "Viennese" quartets in which K. 172 appears (K. 168-173) betrays the recent influence of Haydn's early quartets Opp. 17 (1771) and 20 (1772) both in terms of character as well as form. The K. 172 quartet exemplifies the waning phase of Mozart's transition from a calculatedly impressionable early phase to a mature and distinctive voice. The most obvious divergence from his earlier Italian quartet style is the presence, in the K. 172 quartet, as elsewhere in the Viennese series, of four distinct movements (as opposed to the Italian three). Still, as heard in the Allegro Spiritoso first movement, an air of theatricality with lingering Italian hues can still occasionally be detected. The movement begins with the invocatory pomp of four repeated chords in the upper strings over a descending arpeggio. The subsequent material, with its busy surface and restless melodic contour, sets off the lyrical second theme area. The short, quiet development is underscored by pensive repeated notes in the viola and cello, and abruptly interrupted by the forte opening chords of the recapitulation. The slow second movement is serenely consistent in character and texture, the graceful angles of the violin's moving melody buoyed by a steady stream of interlocking sixteenth note figures in the middle parts and a bare-bones bass line in the cello. The third movement exhibits a similar type of lyricism, enhanced now by fluid rhythmic shifts between straight and triplet beat divisions in the Menuetto; the embedded trio stands out for its minor mode and its quiet, pointillist frailty, with rests interspersed between every note and chord. The finale, marked Allegro assai, shifts to duple meter and, while remaining light in texture and dynamic, is also nimble and rhythmically fluid. Its initial stepwise descending gesture generates much of the subsequent thematic material through diminution, augmentation, and inversion, while a rhythmic interplay between duple and triple divisions helps propel the piece to its clever conclusion.