Mozart and Salieri were classical music’s biggest rivals… or were they? A newly discovered piece rewrites history.

Mozart’s infatuation with a beautiful singer, the reputation of a supposed rival, and an imperial mystery – these elements swirl around a long-lost cantata that was given its first public performance in more than two centuries by Australian soprano Kate Rafferty in Vienna in March, and its Australian premiere in Canberra earlier this month.

The cantata Per la Ricuperata Salute di Ofelia(KV477a) was written by Mozart, Antonio Salieri (still in the popular imagination the resentful saint of mediocrity who murdered Mozart) and the mysterious “Cornetti” in 1785, to mark the recovery from a nervous breakdown of Nancy Storace, the first Susanna in Le Nozze di Figaro. English-born Storace was reputedly the mistress of Emperor Joseph II and the Prince Regent, and – some claim Mozart.

Storace was headhunted to join the emperor’s new Italian Opera Company in 1783.  Although her operatic career in Vienna was brilliant, her private life was less happy.  She married John Abraham Fisher, an English musician twice her age, whose mistreatment of her so incensed the emperor that he banished Fisher.  The year 1785 was calamitous for Storace....