—a complete string trio has survived in Leipzig," says Ulrich Leisinger, head of the International Mozarteum Foundation. "The source was evidently Mozart’s sister, and so it is tempting to think that she preserved the work as a memento of her brother. Perhaps he wrote the trio specially for her.
Now that’s pushed me into (angrily) thinking about Felix Mendelsohn and his likewise talented sister, Fanny (also a composer, and by some accounts a more skilled pianist than Felix), who he often sought out for advice on his own works even though he looked down on her publishing her own compositions. Twisting the knife further, there’s evidence suggesting that some of Fanny’s compositions were published under Felix’s name.