On 26 June 1788, Wolfgang Amadeus Mozart made a new entry in the list of compositions he was keeping: “a short Adagio for two violins, viola, and bass, and a fugue I wrote a long time ago for two pianos”. It is unclear why years after having written the Fugue K 426 in December 1783, he decided to transcribe it for strings and add a dramatic introduction in the manner of a Bach cantata. He seemingly did so at the suggestion of his Viennese publisher Franz Anton Hoffmeister, whose music publishing business had been in operation in Vienna since 1785, and who had published several of Mozart’s works besides the Adagio and Fugue, K 546, including the Piano Quartet, K 478 and the String Quartet, K 499, nicknamed the “Hoffmeister Quartet”. At the time, perhaps Mozart simply needed to immerse himself briefly in his old contrapuntal studies before turning his attention to the complex counterpoint of his Symphony in C major, K 551, known as the “Jupiter Symphony”.
The Adagio and Fugue in C minor, K 546, is routinely played by string quartets and even more often by string orchestras of various sizes. Because the bass line in the autograph is divided in one place into “violoncelli” and “contrabasso”, it is clear that Mozart had a larger ensemble in mind. Basically, however, the music is in four parts, with the dark opening of the Adagio alternating with dramatically tense passages at a static pianissimo dynamic and moving chromatically by semitones. The Fugue gradually departs from its Bachian model, increasingly revealing that its composer belongs to the Classical era. As a whole, the work bears witness to the continuity of German music of the 17th and 18th centuries despite the fact that the works of the great master Bach had nearly fallen into oblivion in Mozart’s day and were appreciated only for their didactic value.
Wolfgang Amadeus Mozart’s Quintet for clarinet, two violins, viola, and cello in A major, K 581, is innovative in its conception as absolute chamber music in the purely modern sense, i.e., in its inimitable presentation of the voice of a woodwind instrument in equal dialogue with other parts. For the first time in music history, instruments so different from each other were perfectly and uniformly balanced and united whilst exploiting their colours and sonic characteristics. In later times, many of Mozart’s successors attempted to write compositions for the same forces, but only one of them succeeded at penetrating deeply to the very essence of the chamber music sound: Brahms.
Mozart’s path to the Clarinet Quintet in A major certainly was not direct. There are two fragments that Mozart composed on commission for his friend, the clarinettist Anton Stadler (1753–1812), but he put them aside and left them unfinished. The Allegro in B flat major (K Anh. 91, K 516c or 580a) for B flat clarinet, two violins, viola, and cello dates from 1787. In September 1789 was working on an Allegro in F major (K Anh. 90, K 580b) for clarinet in C, basset horn, violin, viola, and cellos. The way that movement is composed already closely resembles the Clarinet Quintet, K 581, but this truly beautiful music ultimately also remained unused.
At the time, the Viennese instrument maker Theodor Lotz (1718–1792) was commissioned by Stadler to design a new prototype for a basset clarinet in A, which had an expanded low range compared with a classic clarinet, extending down to a low “A” sounding pitch, using the basset horn design for the low notes. Although Mozart was enthusiastic about the new instrument, it did not survive the test of time because of its mechanical complexity. After Lotz’s death, no one else continued the instrument’s development. Only recently have basset clarinets been made not only with modern designs, but also as replicas of Lotz’s original instruments, which have been used for performing not only this quintet, but also Mozart’s Clarinet Concerto in A major, K 622. However, both compositions are routinely played on a modern A clarinet with adjustments to the part’s range. Events in Vienna took a sudden turn when Mozart began composing the quintet for a third time. It was finished on 29 September 1789, and on 22 December 1789, Stadler premiered the new Clarinet Quintet in A major at a concert of the Tonkünstler-Gesselschaft at Vienna’s Hoftheater playing the new basset clarinet. At the premiere, Mozart played the viola part himself.
Less than two years later, Mozart also wrote his Clarinet Concerto in A major, K 622, for Stadler. The clarinettist was accompanying the composer and his wife on their journey to Prague, where he premiered the concerto on 16 October 1791 and played in the theatre orchestra, performing the obligato clarinet part in an aria from Mozart’s coronation opera Titus. It seems incredible that seven weeks later, Mozart was no longer among the living (he died on 5 December 1791). Lotz died as well a year later, and his heirs tried in vain to collect the fee from Stadler for the making of the basset clarinet. Mozart likewise never received even a penny for the works Stadler had commissioned from him. As Volkmar Braubehrens documents in his marvellous book Mozart in Vienna, at the time of Mozart’s death, the clarinettist owed the composer 500 gulden. Mozart’s widow Constanze tried unsuccessfully not only to remind Stadler of his debt, but also to get him to return manuscripts of Mozart’s compositions. To escape his creditors, Stadler fled to Germany, where, under financial pressure, he did not flinch even from offering Mozart’s compositions as works of his own. In the end, the valuable manuscripts ended up in a pawnbroker’s shop along with a basset clarinet. It took ten years before the works were rediscovered, made available, and published. Thus ended a great musical friendship, the fruits of which included the Clarinet Quintet in A major, K 581. Nonetheless, the work is still sometimes called the “Stadler-Quintett”.
This unique composition radiates a peculiarly poetic magic already from its opening sonata movement. It breathes an air of quiet serenity and joyous wellbeing. Especially in the second movement, Mozart takes advantage of the clarinet’s ability to play cantilena lines and uses its wealth of colours, but none of the other instruments are relegated to merely secondary roles. In the third movement, a menuet with two trios, the first trio is in the minor mode and is reserved for the strings alone. Then in the second trio, the clarinet cheerfully abandons the menuet’s restraint, and the music assumes the character of a Ländler from the outskirts of Vienna. The variations of the fourth movement proceed just as boldly, with virtuosic escapades, a minor-key episode, and a veiled Adagio followed by the return of a carefree, playful mood.