La donna è mobile
From Tardis Wiki, the free Doctor Who reference
La donna è mobile is a song from the Italian opera Rigoletto (1851) by Giuseppe Verdi.
Interpreted by the Doctor
The Third Doctor sang it whilst driving to the Inferno drilling project on Bessie. (TV: Inferno)
The Doctor sang it again during his eleventh incarnation whilst taking a shower. (TV: The Lodger)
Other interpreters
The Italian soldier Tito sang it while lying on his bunk in the base of Snowcap. (TV: The Tenth Planet)