Vocalese is a style or genre of jazz singing wherein lyrics are written for melodies that were originally part of an all-instrumental composition or improvisation. Whereas scat singing uses improvised nonsense syllables in solos, vocalese uses lyrics, either improvised or set to pre-existing instrumental solos. The word "vocalese" is a play on the musical term "vocalise" and the suffix "-ese", meant to indicate a sort of language.