I was reading the score for Mozart’s insertion aria for his own opera Idomeneo “Non Temer Amato Bene”, K. 490. In it, Idomeneo’s son Idamante (scored for soprano; trouser role) expresses his undying love for Ilia.
In the Allegro Moderato section, the sheet music seems to show Idamante singing two voices. What should the soprano do differently here?