Whose music persuaded Hades to let his lover go?

Orpheus played his music for Hades and convinced him to release his wife Eurydice. Only on the condition that Orpheus did not look back even once as he left the underworld to insure his wife was following him. Orpheus did not follow Hades' instructions and looked back, he saw Eurydice there, but lost her again because he broke their agreement.