"La donna è mobile" ("Woman is fickle") is the cynical Duke of Mantua's canzone from Giuseppe Verdi's opera Rigoletto (1851).

The inherent irony, of course, is that it is the callous playboy Duke himself who is mobile. Its reprise in the last act is chilling, as Rigoletto realizes from the sound of the Duke's lively voice coming from within the tavern (offstage), that the body in the sack over which he has grimly triumphed is not that of the Duke after all:

Rigoletto had paid Sparafucile, an assassin, to kill the Duke but Sparafucile deceived him by killing Gilda, Rigoletto's daughter, instead. The aria is famous as a showcase for tenors. It has been recorded by Enrico Caruso, Mario Lanza, Plácido Domingo, Luciano Pavarotti, Juan Diego Flórez, Jussi Björling and hundreds of others...including now Seattle's own Izzy Anderson

Before this song's first public performance (in Venice), it was rehearsed under very tight secrecy: a necessary precaution, because it proved to be very catchy and within a day or two after its first public performance every gondolier in Venice was singing it.