Lange (née Weber), (Maria) Aloysia (b. Zell or Mannheim, c.1761; d. Salzburg, 8 June 1839). German soprano, Mozart's sister-in-law and daughter of Fridolin Weber (b.? Zell im Wiesental, 1733; d. Vienna, 23 Oct. 1779). Mozart first met Lange during his stay in Mannheim in 1777–8, when he gave her musical instruction and composed for her the concert arias K294, K316 and probably the early version of K538; he also fell in love with her, mooting to Leopold Mozart his plans to take her to Italy (an idea to which his father objected strenuously). In 1778 she moved to Munich where she made her debut in Schweitzer's Alceste; shortly afterwards she was engaged at the Nationaltheater in Vienna. From 1782, when German opera was removed to the Kärntnertortheater and Italian comic opera reinstated at the Burgtheater, she was a leading singer of the Italian troupe; Mozart composed the arias ‘Vorrei spiegarvi, oh Dio!’, K418 and ‘No, che non sei capace’, K419 for her debut as Clorinda in Anfossi's Il curioso indiscreto. Apparently Lange fell out of favour and in 1785 was transferred to the less prestigious Kärntnertortheater, where among other roles she sang Konstanze in Mozart's Die Entführung aus dem Serail; occasionally she was engaged for the Italian opera, most notably in 1788 when she sang the role of Donna Anna at the Viennese premiere of Don Giovanni.