 Mozart completed this recitative and aria in Munich on 8 January 1779, as an insertion aria for the opera "Alceste" by Christoph Willibald Gluck.It was written specifically to showcase the superlative vocal skills of Mozart's future sister-in-law, Aloysia Weber, who was only 18 at the time.However, sopranos who are able to cope with the aria's demands have been few and far between, and hence the aria is usually omitted from performances of "Alceste".