Dido and Aeneas, opera in three acts: Act 2, Scene 1. Prelude for the Witches: “Ecco pur ch'a voi ritorno” (Sorceress, First Witch) / “Harm's our delight and mischief all our skill” (chorus) by René Falquet , Chœur de l'Opéra de Lausanne , Glenys Linos , Tiziana Sojat , Ensemble Instrumental de Lausanne , Michel Corboz