Maria Anna Walburga Ignatia "Marianne" Mozart (30 July 1751 – 29 October 1829), nicknamed Nannerl, was a highly regarded musician from Salzburg, Austria.

In her childhood, she made tremendous progress as a keyboard player under the tutelage of her father Leopold, to the point that she became a celebrated child prodigy, touring much of Europe with her parents and her younger brother Wolfgang Amadeus Mozart.

"Just imagine a girl 11 years of age who can perform on the harpsichord or the fortepiano the most difficult sonatas and concertos by the greatest masters, most accurately, readily and with an almost incredible ease, in the very best of taste."

His daughter, eleven years of age, plays the harpsichord in the most brilliant manner; she performs the longest and most difficult pieces with an astonishing precision."

(from Baron Friedrich Melchior Grimm's Correspondance littéraire, 1 December 1763)[7] "His daughter, aged eleven, plays the harpsichord in a distinguished manner; no one could have a more precise and brilliant execution."

The first occasion was in the Hague in November 1765, during the Grand Tour: the Mozarts averted their daughter's death by changing doctors at the last minute, with the altered treatment leading to her survival.

In her sickbed she babbled in five languages (helping to distract her frightened little brother), and was administered the Roman Catholic sacrament of extreme unction.

The smallpox was likely contracted in Vienna (it struck both children), but the actual illness took place while the Mozarts were staying in Olomouc, in a vain effort to escape the disease.

He sought to prepare Wolfgang for a Kapellmeister position, which would offer a steady and substantial income which would enable him to support the entire family as his parents aged.

The family frequently attended the theatre when a company was in town (they befriended Mozart's later collaborator Emanuel Schikaneder when he brought his troupe to Salzburg).

In 1780, Marianne took the last trip of her life outside the Salzburg area, visiting Munich to attend the premiere of her brother's opera Idomeneo, performed at Carnival time.

Around the summer of 1783, Marianne then aged 32, developed a relationship with Franz Armand d'Ippold, who was a 53-year-old[19] civil servant in the Salzburg court who directed a school for aristocratic boys.

[24] Marianne was the daughter of, and had been taught exclusively by, Leopold Mozart, who had independent fame for his pedagogy and was the author of a famous violin text.

By the testimony of Albert von Mölk, a family friend, Marianne was herself highly effective as a teacher: In the last years of her unmarried state, which she spent in the home of her father, she gave lessons in piano playing to several young women of Salzburg; and even to the present, one can single out the students of Nannètte Mozart from all the others by the care, precision , and correct fingering in their playing.

During the period between her youthful performing career and her departure from Salzburg, when Leopold was at home, he attended to aspects of Marianne's musical education that had been left as gaps when the goal had been to produce a piano virtuoso: realization of figured bass, accompaniment of singers, and transposition.

[29] Eventually, on 23 August 1784 Marianne, aged 33, married a magistrate named Johann Baptist Franz Freiherr von Berchtold zu Sonnenburg (1736–1801),[30] and settled with him in St. Gilgen, a village in Austria about 29 km[31] east of the Mozart family home in Salzburg.

[34] The government had built a substantial residence and headquarters for the Pfleger in 1720, and this is the home (where her late mother had spent her first four years) into which Marianne moved on her marriage.

[39] The damp lakeside location of Marianne's new home, which had caused trouble in her grandfather's time by putting mildew on official documents, was also problematic for piano actions.

Nevertheless, Marianne persevered in her career as a pianist, practicing three hours a day and even managing to play, probably in very small ensembles, her brother's new concertos.

[40] During the early years of her marriage Marianne conducted an extensive correspondence with Leopold, who until his death (on 28 May 1787) attempted to provide what help he could from a distance, running errands and reporting news.

"[42] An unusual episode in Marianne's life occurred when she gave birth (27 July 1785) to her first child, a son who was named Leopold after his grandfather.

Biographer Maynard Solomon attributes the arrangement to Leopold's wish to revive his skills in training a musical genius, as he had done with Marianne's brother.

Wolfgang's contributions, often added on to Leopold's letters, are affectionate, frequently teasing; they included some of the scatological and sexual wordplay in which he indulged with intimates.

[45] However, a widely noted fact about relationship between the two siblings is that the last letter from Wolfgang to Marianne is dated 1788, fully three years before his death, leading some scholars, e.g. Solomon,[46] to infer that there was a falling out.

Otto Jahn likewise judged that the two siblings may have severed their relationship, and suggested various reasons:[47] that Wolfgang had essentially abandoned his family when he moved off to Vienna, that she did not care for his wife Constanze, and perhaps some friction over the disposal of Leopold's estate in 1787.

[3] Eva Rieger writes in the New Grove: [Marianne] obviously adopted the prescriptive and pedagogical literature of the late Enlightenment and lived as the epitome of contemporary ideas of femininity (piety, self-sacrifice, propriety, modesty).

[58] Halliwell narrates an episode in her religious experience: On Good Friday 1779 she and her friend Katherl Gilowsky embarked on a pious round of visits to sixteen different churches to mark the occasion.

At one church (the Kajetanerkirche), they climbed a stairway on their knees;[59] the day was concluded by a visit to Holy Trinity to hear the special music for Good Friday.

Rieger notes that she was "an avid reader and theatre-goer"; she had good friends in Salzburg (Katherl Gilowsky in particular appears in the records repeatedly), and she participated fully in a rich family life.

Readers are cautioned to enjoy such works without trying to extract facts from them; Hilscher's words "the wish is father to the thought" are widely applicable in this literature.