Anita O'Day (October 18, 1919 – November 23, 2006) was an innovative American jazz singer celebrated for her sharp sense of rhythm and dynamic vocal style. Known as a “song stylist,” she broke the mold of the traditional big band vocalist by rejecting stereotypes and presenting herself as a cool jazz musician, often performing in a band jacket and skirt instead of an evening gown. O'Day changed her surname from Colton to O'Day, inspired by the slang for money, reflecting her bold and modern approach to both music and image.