Complex sentence: It was in Lyon that he first heard an orchestra, attended an opera ("Boris Godunov ") and met the well-known soprano Ninon Vallin, who asked him to accompany her in arias from"Aida " and"La Damnation de Faust".
Split into simpler sentences: It was in Lyon that he first heard an orchestra and attended an opera ("Boris Godunov "). He also met the well-known soprano Ninon Vallin, who asked him to accompany her in arias from"Aida " and"La Damnation de Faust".