Wolfgang Amadeus Mozart (1756–91) was a prolific and highly influential composer of Classical music. His enormous output of more than six hundred compositions includes works that are widely acknowledged as pinnacles of symphonic, chamber, piano, operatic, and choral music. And most important of all, he also composed for the glass armonica!
Mozart was born in Salzburg, now in Austria but then in the Holy Roman Empire. His only sibling who survived beyond infancy was an older sister: Maria Anna, nicknamed Nannerl. Mozart's father Leopold (1719–1787) was one of Europe's leading musical teachers and a noted composer in his own right. Leopold gave up composing when his son's outstanding musical talents became evident. They first came to light when Wolfgang was about three years old, and Leopold, proud of Wolfgang's achievements, gave him intensive musical training, including instruction in piano, violin, and organ. Leopold was Wolfgang's only teacher in his earliest years.
During his formative years, Mozart made several European journeys, beginning with an exhibition in 1762 at the Court of the Elector of Bavaria in Munich, as well as the Imperial Court in Vienna and Prague. A long concert tour spanning three and a half years followed, taking him with his father to the courts of Munich, Mannheim, Paris, London, The Hague, again to Paris, and back home via Zurich, and Munich. During this trip Mozart met a great number of musicians and acquainted himself with the works of other great composers. A particularly important influence was Johann Christian Bach, who befriended Mozart in London in 1764–65. (You'll recall that J.C. Bach was also very helpful to the Davies sisters.) They again went to Vienna in late 1767 and remained there until December 1768. On this trip Mozart contracted smallpox, and his healing was considered by Leopold as a proof of God's intentions concerning the child. (As we have seen, Kirchgaessner was blinded by smallpox.)
After one year in Salzburg, three trips to Italy followed: from December 1769 to March 1771, from August to December 1771, and from October 1772 to March 1773. During the first of these trips, the Mozarts were actually standing on the balcony of their lodgings when they saw the Davies family arriving in Milan. Leopold writing to his wife on 21 September  said:
A few days ago Miss Davies arrived here and drove past our house in the mail coach. I recognized her and she saw us, for we happened to be standing on the balcony. A few hours later I went to call on her at the 'Three Kings', which is not very far off, as I guessed that she would be staying there, since it is the most respectable inn. She, her sister, her father and her mother could hardly express their joy. I told their servant where Herr Hasse was staying and very soon his daughter appeared, who also was beside herself with delight, for they have been most cordial friends since they met in Vienna. They all asked for you at once and they send you their greetings. You will surely remember Miss Davies with her armonica?1
When Leopold says "I recognized her and she saw us" and "You will surely remember Miss Davies with her armonica" it is clear that by 1771 (the date of his letter) the Mozarts (including Wolfgang's mother) must have been already acquainted with the Davies sisters and Marianne's armonica. When did that occur? Comparing their timelines may give us a clue:
|Year||The Davies||The Mozarts|
|1762–5||Munich, Paris, London, The Hague, Zurich|
We know that both Mozart and the Davies were giving concerts in London in 1765. Here we get some idea of what those concerts may have been like:
Formal concerts during the daytime required the special permission of the Lord Chamberlain. Most daytime concerts were therefore quite different in nature, being marketed as exhibitions. In much the same way as curiosities such as 'the Learned Pig' or a mechanical chess-player, the young Mozart was in 1765 put on display, carrying out keyboard tricks, playing the harpsichord with a handkerchief over his hands, and so on. The performances took place initially at the Mozart's Soho lodgings, later at the decidedly down-market Swan and Hoop Tavern in Cornhill. Mozart was in fact contributing to a spate of daytime concerts in the early 1760s, coinciding with a fashion for the musical glasses; thus in 1761 one Drybutter could be heart at his house every day from noon until two o'clock, playing ten tunes to each set of company for 1/-. The glasses were one of the instruments of Ann Ford, who (contrary to some reports) reappeared at the Spring Garden Room giving half-a-crown daytime appearances from 15 October 1761 onwards. … An additional incentive on one occasion in 1762 was the presence of three Cherokee chiefs, who were hawked round numerous venues this summer.2
Marianne Davies was giving performances in London at the time. So they may have met around 1765 in London, or perhaps around 1769 in Vienna.
In 1773 father and his 17-year-old son were in Vienna and encountered the armonica again at Franz Mesmer's house. Leopold wrote home to his wife:
Herr von Mesmer, at whose house we lunched on Monday, played to us on Miss Davies's harmonica or glass instrument and played very well. It cost him about fifty ducats and it is very beautifully made.3
A few weeks later Leopold brought up the armonica again, mentioning to his wife that Wolfgang himself tried playing Mesmer's instrument:
Do you know that Herr von Mesmer plays Miss Davies's harmonica unusually well? He is the only person in Vienna who has learnt it and he possesses a much finer glass instrument than Miss Davies does. Wolfgang too has played upon it. How I should like to have one!4
In a letter of May 28, 1778, however, writing about the playing of Besozzi, a famous oboist, Leopold's opinion of the armonica seems to have changed:
This mezza di voce was too frequent for my taste and has the same melancholy effect on me as the tones of the armonica, for it produces almost the same kind of sound.
In 1777, accompanied by his mother, Mozart began a tour of Europe that included Munich, Mannheim, and Paris. In Mannheim he became acquainted with members of the Mannheim orchestra, the best in Europe at the time. He fell in love with Aloysia Weber, who later broke up the relationship with him. He was to marry her sister Constanze some four years later in Vienna (over his father's vehement objections). During his unsuccessful visit to Paris, his mother died (1778).
In 1780, Idomeneo, widely regarded as Mozart's first great opera, premiered in Munich. The following year, he visited Vienna in the company of his employer, the harsh Prince-Archbishop Colloredo. When they returned to Salzburg, Mozart, who was then Konzertmeister, became increasingly rebellious, not wanting to follow the whims of the archbishop relating to musical matters, and expressing these views he soon fell out of favor with him, and was ultimately fired. Subsequently Mozart chose to settle and develop his own freelance career in Vienna after its aristocracy began to take an interest in him. Mozart made Vienna the "base of his operations" for the rest of his life.
As we have seen, Mozart heard Marianne Kirchgaessner in 1791 and was finally inspired to compose for the armonica—with which he had been acquainted since at least his teens. In the spring of 1791 he composed:
- The Adagio in C (K617a/K356—click here for the score) for solo armonica
- The Adagio and Rondo (K617—click here for the score )—a quintet for armonica, flute, oboe, viola and cello
- He started a third quintet—a Fantasia in C (K616a—click here for the score), also for armonica, flute, oboe, viola and cello, of which he only completed the first 13 fragmentary bars
Kirchgaessner performed the quintet at least (K617) and presumably also the solo Adagio. That summer Mozart wrote his famous opera Die Zauberflöte ("The Magic Flute"), in the fall his Requiem, and died that December.