Cousser (Kusser), John (Johann) Sigismond (1660?–1727), composer and master of the king's music in Ireland, was born in Pressburg (later Bratislava) and baptised on 13 February 1660, the son of a Hungarian cantor and composer. In 1674 he moved with his parents and sister to Stuttgart and later spent six years in Paris, where he may have studied with the French composer Jean-Baptiste Lully. He was in the service of the court at Baden-Baden in 1680, and in 1683 was appointed to the court of Ansbach, where he trained the court violinists in the French style of playing. The previous year he had published in Stuttgart six ‘Ouvertures de théatre’ in the French style. Walther (1732) states that he travelled throughout ‘all of Germany, and it would be difficult to find a place where he was not known’, adding that he was unable to stay long in any one place because of his volatile and fiery temperament. This may refer to the period between his departure from Ansbach in 1683 and 1689, when he was appointed court Kapellmeister in Braunschweig-Wolfenbüttel.
In August 1691 he married Hedwig Melusine von Damm, with whom he had three daughters and one son. Following disputes with Friedrich Christian Bressand, court poet, manager of the court opera, and librettist of a number of Cousser's operas, in 1694 he left Braunschweig-Wolfenbüttel and spent several years as music director of the opera in Hamburg. Apart from selections subsequently published of arias from ‘Ariadne’ (Braunschweig, 1692) and ‘Erindo’ (Hamburg, 1694), none of the music of the eight or more operas he composed during this period is known to have survived. He subsequently travelled again throughout Germany, and in 1698 was in Stuttgart, where he was appointed Oberkapellmeister in 1700. The discovery in 2005 of the score of his opera ‘Adonis’, produced in Stuttgart in 1699 or 1700, represents the only complete opera by Cousser known to have survived. In about 1701 he visited Italy, and in 1704 moved to London, where he worked as a private music teacher and gave occasional public performances.
In July 1707 Cousser travelled to Dublin, where he was to live for the rest of his life. From 1708 until his death he composed the annual ode or ‘Serenata’ for the sovereign's birthday performed usually at Dublin Castle, suggesting that his position may have been as ‘state composer’ under William Viner (qv), master of the state music in Ireland, whom he succeeded in 1716. The printed libretti of eighteen of Cousser's birthday odes and his coronation ode for George I (1714) survive (Cashel, Dean and Chapter library; NLI; TCD; BL; King's Inns Library; Bodleian Library, Oxford; Houghton Library, Harvard), the last being for King George II on 30 October 1727, two months before Cousser's death. At least some of these serenatas appear to have been staged, but only the music for that of 1711 has survived (Bodleian Library). On 16 June 1713 a ‘Te Deum’ by Cousser was performed in Christ Church cathedral to mark the Treaty of Utrecht, and on the same evening he and Viner presented a celebratory ode, 'An idylle on the peace', in Smock Alley theatre, the music and libretto for which survive (Staats- und Universitätsbibliothek, Hamburg; Huntington Library, San Marino). A further serenata, the music for which survives in Cousser’s hand and was probably composed by him, commemorates the late William III (also in Hamburg). Although he described himself in 1711 as ‘Chappel-Master of Trinity College’, his name does not appear in the records of Trinity College chapel, where Daniel Roseingrave (qv) the elder (d. 1727) was organist at the time; this title may have been granted by Dublin Castle, which had close links with the university. According to Walther, Cousser made a particular study of music theory while in Dublin with a view to taking a doctorate. Nothing came of this plan, although his commonplace book contains lengthy notes from counterpoint treatises by Athanasius Kircher and Christoph Bernhard.
Cousser named his wife, two surviving daughters, and his sister in Stuttgart as principal beneficiaries in his will dated 21 December 1727 and probated on 27 December. He bequeathed to his nephews ‘all the musical papers and compositions which I shall die possessed of’.
The paucity of surviving music by Cousser precludes a fuller assessment of his importance within the wider European context, but he clearly played a significant role in the introduction of French and Italian musical styles to Germany. Within the Irish context he is important as the first continental European composer of any stature to settle in Ireland, and he certainly must have played a major role in the introduction of European musical styles into the culturally isolated world of early eighteenth-century Dublin.