The Doctor as Canio/Pagliaccio from Pagliacci
Pagliacci was an Italian opera from the late 19th century on Earth.
Pagliacci was one of the operas being played at the Dorothy Chandler Pavilion, Los Angeles in 1996. (VOY: "Future's End, Part II")
For his first performance on the Qomar homeworld in 2376, The Doctor reproduced the backdrop of a production of Pagliacci at the Teatro alla Scala. (VOY: "Virtuoso")
Pagliacci ("Clowns") was composed by Ruggero Leoncavallo and first performed in 1892.