Mozart wrote from Vienna to his father Leopold in Salzburg on April 8, 1781:

Today (for I am writing at eleven o’clock at night) we had a concert, where three of my compositions were performed—new ones, of course; a rondo for a concerto for Brunetti; a sonata with violin accompaniment for myself, which I composed last night between eleven and twelve (but in order to be able to finish it, I wrote out only the accompaniment for Brunetti and retained my own part in my head); and then a rondo for Ceccarelli, which he had to repeat.

The three pieces were his Rondo for violin and orchestra (K. 373), the present G major Sonata, and the aria in rondo form “Or che il ciel” (K. 374). The occasion for this chamber concert was a command performance for the archbishop of Salzburg, who was visiting Vienna and had summoned a group of Salzburg musicians to perform for him and his father, Prince Rudolf Joseph Colloredo. Mozart had brought little music with him, and hence had to compose with haste. Clearly for him it went without saying how quickly the participants—among them violinist Antonio Brunetti and male soprano Francesco Ceccarelli—had to learn their parts, but it’s still astounding!

The letter is informative in so many ways. First, we note how quickly Mozart was able to compose music of enduring substance, and, second, how for him the mechanical process of writing down the composition was something that could be taken care of later, for the creative part had already been accomplished in his mind. Further, we are reminded how Mozart viewed the present Sonata—and his others in this genre—as keyboard sonatas, with violin accompaniment.

Mozart’s manuscript of the G major Violin Sonata gives testimony to the haste of the work’s genesis, but nothing in the listening experience betrays anything other than thoughtfulness having been lavished upon the piece. The first movement is remarkable for its serene, extended opening section in the major mode, which is almost a movement in itself. The suspenseful open ending (on the dominant) unleashes a stormy G minor fast section in sonata form, in which the two instruments unleash pelting rain, lightning bolts, and sighing figures with equal passion.

The second and final movement is a graceful theme with five charming variations, followed by a return to the theme with a decorative coda. Of special interest is Mozart’s dramatic use of minor-mode harmonies at the outset of the second half in variations 1, 2, 3, and 5. What is so remarkable is that this striking feature is not present in the original theme. The entire course of the fourth variation unfolds in the minor mode except for a brief hint of major at the analogous spot. Variation 5 returns to the major mode with its sweetly ornamented melody supported by pizzicato broken chords in the manner of a serenader’s guitar. The “minor-mode switch” makes its most theatrical impression in this final variation.

© Jane Vial Jaffe