String Quartet in A major K.464 
4. Allegro ma non troppo
The A major Quartet is the fifth in Mozart’s set of six quartets dedicated to his great friend Joseph Haydn. It was written at the time of Mozart’s greatest triumphs, when his name was on every lip due to the spectacular success of his subscription concerts.
The friendship between the two composers is one the great stories of musical history, matched only by that of Brahms and Schumann. Mozart’s determination to impress Haydn and to win his respect is nowhere more apparent than on the manuscript scores for these quartets, nowhere else are there so many corrections strewn above crossed-out tempi and dynamic markings. And the evening when the two composers sat down together to play through the last three quartets in the set with Haydn playing first violin and Mozart viola speaks worlds about their mutual understanding of each other’s achievement.
The most obvious difference between the two sets is that Mozart’s are easily twice as long and the increased scale indicates a much greater ambition for this new chamber music combination. Out of the older composer’s invention the younger one created a new world, which was itself to inspire the next in the succession. Beethoven’s A major Quartet in his Opus 18 set is clearly composed as a homage to Mozart’s A major.
Mozart’s opening movement is built on the briefest of material, more questions and answers than fully formed themes. The first subject, for instance, consists of a query put by the first violin and a vigorous unison reply; the second subject is even less substantial, three rising notes and a graceful run of triplets. The exposition closes with a restatement of the opening before we are launched into the complex many voiced development based entirely on the questioning figure and its answer. The recapitulation is straightforward and the movement ends uneventfully.
The Minuet is based on another terse phrase, almost as if asking what is the question for this answer. The questioning figure gets tossed hither and thither in many different voices, some harsh, some gentle. The Trio is more euphonic though the desire to embellish and decorate soon takes over.
The D major Andante is a theme with six variations and a coda. The theme is quiet and reflective, the kind of beauty that succeeds by understatement in abrupt contrast to the florid embellishments of the first variation. The second one takes a completely new path, establishing a secondary theme to be explored in the drum-beat sixth variation. The third variation plunges into an aura of mystery led by Mozart’s viola before we are dragged even further afield into dramatic and gloomy D minor. The fifth variation retains the air of uncertainty before all is made clear with the extraordinary drum taps of the sixth, which continue right into the coda where each instrument gets to hold the drumsticks, though the cello gets the most fun.
The surprises are not over yet for this is the movement that Beethoven relished. It is ostensibly in sonata form though you would be forgiven if you thought it was an endless imitative hot pursuit of the opening ideas, until the sudden intrusion in the middle of the development of a lofty chorale in D major, which also returns in the recapitulation. The coda picks up on Haydn’s practice of joke endings to give a witty and enigmatic close.