Orpheus and Eurydice is a tragic love story. This is how it goes...
Orpheus is the son of Apollo and Calliope. He has such a musical talent even nature itself moves to hear him. He fell in love with an oak nymph named Eurydice.
They get married, but soon after, she dies of a snake bite and her soul is sent to the Underworld.
Orpheus is wrought with such grief, he goes to the Underworld to get her back.
He plays for Charon, the ferryman of the River Styx in order to pass into the Underworld. When he gets to Hades' and Persephone's thrones, the plays for them as well. Poor Cerberus and Persephone could not stand his sorrowful music.
Hades lets Orpheus have his wife back on one condition: that he doesn't look back until she leaves the Underworld.
Long story short, he looks back and loses her again. After that, he lets himself be ripped apart by jealous women and his pieces get thrown in the river.
Harry Potter and the Sorcerer's Stone:
Harry plays a flute for Fluffy to make him fall asleep so he can go underneath him to get the sorcerer's stone, like Orpheus who does it to get to the underworld and save his beloved Eurydice.
"He put Hagrid's flute to his lips and blew. It wasn't really a tune, but from the first note the beast's eyes began to droop. Harry hardly drew breath. Slowly, the dog's growls ceased -- it tottered on its paws and fell to its knees, then it slumped to the ground, fast asleep" (Rowling 275).