(1750–1825), Italian composer, born in Legnago; first opera, Le donne letterate, produced in Vienna (1770); made court composer, then Hofkapellmeister (music director) by Emperor Joseph II; composed operas for companies in Austria, France, and Italy; best known for his French opera Tarare (1787); last opera performed in 1804, then composed sacred music; friendly with Joseph Haydn and Ludwig van Beethoven; relationship to Mozart subject of speculation (as explored in Peter Shaffer's play Amadeus), including unfounded rumor that he tried to poison Mozart.