Famous celebrities acting in animated features is nothing new, and it dates back at least to 1955, when Lady and the Tramp hit theaters. Headlining the cast: Miss Peggy Lee, an extremely popular American singer in the vocal jazz and traditional pop styles in the pre-rock ‘n’ roll era. Lee lent her voice, with which mainstream audiences were extremely familiar in 1955, to the voices of human Darling and the cats Si and Am, and also helped write six songs on the film’s soundtrack. Adults who saw Lady and the Tramp during its initial release must have enjoyed or at least appreciated Lee’s contributions, while grown-ups who watch it now would at least be more familiar than their kids are with the legendary singer of “Fever,” “Mañana,” and “Big Spender.” [Source: Looper]