They signed up with Paramount Studios in 1945. It was while at Paramount that they wrote their most lasting songs, beginning with "Buttons and Bows," an alliterative ditty first sung by Bob Hope while hanging out the back of a covered wagon in "The Paleface" (1948). Two years later, they penned "Mona Lisa," an unusual, faux-Italian ballad about a lover's need to understand an unknowable lady. It went on to become a classic so familiar that almost anyone could be called upon to sing its opening bars: