In one opera, he sings the aria "Possente spirto, e formidabil nume" in an attempt to put another figure to sleep.  
In one opera, he sings the aria "Possente spirto, e formidabil nume" in an attempt to put another figure to sleep.  He is issued a warning by the counter-tenor Ascalax in an opera about the "Marvelous Constancy of Love" by Telemann.  Alice Munro's Dance of the Happy Shades comes from a Christoph Gluck opera about this figure.  Subject of an early opera by Monteverde, for 10 points, name this figure from Greek mythology who tries to retrieve Eurydice from the underworld.
In one opera, he sings the aria "Possente spirto, e formidabil nume" in an attempt to put another figure to sleep.  
{Orpheus} [or {Orfeo}]