The Magic Flute, an opera by Mozart (Die Zauberflöte). The “flute” was bestowed by the powers of darkness, and had the power of inspiring love. Unless purified the love was only lust, but, being purified by the Powers of Light, it subserved the holiest purposes. Tamino and Pamina are guided by it through all worldly dangers to the knowledge of Divine Truth.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894