The String Quartet in D major, K. 575, is the first of the three Prussian Quartets—the last string quartets Mozart ever wrote. In April of 1789 he had left Vienna for Potsdam with his pupil, Prince Karl Lichnowsky (later Beethoven’s patron), who was to introduce him to King Friedrich Wilhelm II of Prussia. The king, like his flutist/composer uncle, King Friedrich Wilhelm I, and his pianist/composer cousin, Prince Louis Ferdinand, was a great music lover—his instrument was the cello. Mozart hoped the visit would result in some financial gain, but all he received was a small amount of money and a commission to compose “six easy clavier sonatas for Princess Friederike and six quartets for the king.”

When Mozart got back to Vienna his situation was no better. He was constantly begging money from friends, who this time did not answer his requests; his wife fell seriously ill; and he himself was suffering from rheumatism, toothaches, headaches, and insomnia. He composed one quartet, K. 575 in D major, but waited almost a year before adding two more, K. 589 in B-flat major and K. 590 in F major. He never wrote the other three, nor did he complete the set of sonatas for the princess. He sold the three quartets to a publisher “for a mockery of a fee, only to lay my hands on some money to keep myself going.”

In order to highlight the king’s instrument, Mozart wrote significant cello parts in high register, which he balanced with soloistic opportunities for the other instruments—a style called “quatuor concertant,” which was particularly popular in Paris. Here in the D major Quartet Mozart featured solo cello writing in all movements, whereas in the second quartet the cello comes to the fore only in the first two movements and in the third primarily in the first movement. It seems the image of the cello-playing king receded as time went on.

Mozart chose the relaxed tempo marking “Allegretto” for three of the D major Quartet’s movements. He emphasizes the opening movement’s delicate quality by giving the rare directive “sotto voce” (in an undertone, subdued) at the outset and at the start of the recapitulation. The first violin, then viola, present the main theme, with equal prominence given to the cello when it enters with the second theme in high register. Mozart marks this “dolce” (sweetly), another of his exceptional directives.

The Andante, his only non-Allegretto movement, is only moderately slow—a walking tempo—further minimizing the tempo contrast between movements. His lovely melody bears enough similarity to his 1785 song “Das Veilchen” (The violet) to have given that nickname to the Quartet on occasion. The arching phrases in the middle section of this A-B-A form also feature the cello as an equal conversationalist.

An introductory ornament and light staccato repeated notes, both essential thematic elements, give verve to this elegant Menuetto. The cello particularly comes to the fore in the middle trio section, presenting a singing melody in response to the violins’ lightly tripping invitation.

The cheerful finale combines both sonata and rondo form with a recurring main theme introduced by the cello with viola counterpoint. Many commentators have pointed out the similarity of the main idea to the that of the first movement, suggesting a possible anticipation of Romantic composers’ interest in cyclic unity. Mozart’s astounding but seemingly effortless contrapuntal writing throughout the movement makes refrains, episodes, and development alike a witty and elegant experience.

© Jane Vial Jaffe