(Maria) Constanze [Constantia] (Caecilia Josepha Johanna Aloisia) Mozart [née Weber; later Nissen]

(b Zell, Wiesental, 5 Jan 1762; d Salzburg, 6 March 1842). Soprano, wife of (3) Wolfgang Amadeus Mozart and later of his biographer Georg Nikolaus Nissen. She was the third of four daughters of the bass, prompter and copyist Fridolin Weber, and thereby related to the composer Carl Maria von Weber (see Weber). She first met Mozart in 1777–8 in Mannheim; he fell in love with her elder sister Aloisia, who rejected him. Constanze moved with her family to Vienna in September 1779; from 2 May 1781 Mozart lodged with her mother, and on 4 August 1782 married Constanze in the Stephansdom. There were six children, of whom two, (5) Carl Thomas and (6) Franz Xaver Wolfgang, survived to maturity. During a visit to Salzburg, she sang one of the soprano parts in a performance at the abbey of St Peter of the Kyrie and Gloria of her husband’s Mass in C minor k427/417a (26 October 1783).

After Mozart’s death she was destitute and was allowed a pension of one third of his salary. She attempted to improve her financial position by arranging concerts with his works in various cities, herself singing in several of them. She organized several performances of La clemenza di Tito. In 1797 she had a vocal score of Idomeneo arranged from Mozart’s autograph and published by Breitkopf & Härtel, though without financial success, and in 1799 she sold his remaining manuscripts to the publisher André after first having them set in order by Abbé Maximilian Stadler and Nissen, who in part managed her affairs. Nissen was a Danish diplomat; she probably first met him in 1797 when he lodged in rooms in her house. They were married on 26 June 1809 in Pressburg (Bratislava) Cathedral. There were no children of this marriage. In 1810 the couple moved to Copenhagen and then, probably in 1821, to Salzburg, where Nissen collected materials for his biography. He died on 24 March 1826, however, before its publication: Constanze had it completed (by Johann Heinrich Feuerstein, who cheated her) and saw it through the press. Early 20th-century scholarship severely criticized her as unintelligent, unmusical and even unfaithful, and as a neglectful and unworthy wife to Mozart. Such assessments (still current) were based on no good evidence, were tainted with anti-feminism and were probably wrong on all counts. Mozart’s letters prove his devotion to her. Evidence about her dates mostly from after 1791; the travel diaries of Vincent and Mary Novello (1829) are especially revealing. Her diary (1828–37) and correspondence show a capable businesswoman (she died in comfortable circumstances) and devoted mother. But she was an unreliable witness and told many lies about the Requiem, whose completion she had organized: she was of course an interested party. Many of the myths surrounding Mozart’s death probably stem from her. Three portraits survive (the most celebrated from 1782 by her brother-in-law Joseph Lange; fig.15) and a fuzzy daguerreotype.

Carl Thomas Mozart

(b Vienna, 21 Sept 1784; d Milan, 31 Oct 1858). Second and elder surviving son of Wolfgang Amadeus and Constanze Mozart. Without finishing his schooling, for some of which he was under Franz Xaver Niemetschek in Prague, he went to Livorno in 1797 to begin his apprenticeship with a commercial firm. He planned to open a piano business in the following years, but the project failed for lack of funds. He moved to Milan in 1805 and studied music with Bonifazio Asioli, but gave up his music studies in spring 1810 and became an official in the service of the Viceroy of Naples in Milan. In that year his mother gave him his father's piano. His relationship with his stepfather Georg Nikolaus Nissen was particularly happy. He several times visited Salzburg, notably for the unveiling of the Mozart monument in 1842 and at the centenary celebrations in 1856, and Vienna. Much of his correspondence was published in the Mozarteum Mitteilungen (1918–21, 1961).