 The singing voice of the frog is provided by  Bill Roberts (VIII) (qv), a popular Hollywood nightclub singer of  the 1950s. Many sources erroneously credit Terence Monk (qv) with  supplying the singing voice of the frog. This error appears to be  rooted in an interview in which Chuck Jones (I) (qv) identified  him as such. However, he was not the baritone heard in the film. The  confusion may have been caused by the fact that Jones did use Monck  in "The Cat Above and the Mouse Below", where he sang "Largo al  factotum" (from Rossinis "Il barbiere di Siviglia"/"The Barber of  Seville").