In Marble Halls - Jobbing actors standing in a theatre bar discussing their fortune, both successful and not, each privately hoping their luck will turn out better than their companion's, because.... ...this lyric is said to bring bad luck if whistled or sung in a theatre! "I Dreamt I Dwelt in Marble Halls" or "The Gipsy Girl's Dream" is a popular aria from 'The Bohemian Girl', an 1843 opera by Michael William Balfe, with lyrics by Alfred Bunn. It is sung in the opera by the character Arline, who is in love with Thaddeus, a Polish nobleman and political exile. The song has been satirised repeatedly as this caricature shows!