The Magic Flute

The Magic Flute was a music piece by Wolfgang Amadeus Mozart. (PROSE: The Secret in Vault 13) The Seventh Doctor once whistled an aria from it. (PROSE: The Death of Art)

The Doctor was present at the premiere of The Magic Flute. (PROSE: The Secret in Vault 13)

K9 once played The Magic Flute for Romana in her presidential office on Gallifrey. She found the music, or at least the specific recording of it, wanting. When asked whether the piece was The Magic Flute, she replied with only four, biting words: "It purports to be." (AUDIO: Weapon of Choice)

Behind the scenes
While not stated in the stories above, in the real world The Magic Flute is an opera, which premiered in Vienna in 1791.