Few female singers matched the hard-swinging and equally hard-living Anita O'Day for sheer exuberance and talent in all areas of jazz vocals. Though three or four outshone her in pure quality of voice, her splendid improvising, wide dynamic tone and innate sense of rhythm made her the most enjoyable singer of the age. O'Day's first appearances in a big band shattered the traditional image of a demure female vocalist by swinging just as hard as the other musicians on the bandstand, best heard on her vocal trading with Roy Eldridge on the Gene Krupa recording "Let Me Off Uptown." After making her solo debut in the mid-'40s, she began incorporating bop modernism into her vocals and recorded over a dozen of the best vocal LPs of the era for Verve during the 1950s and '60s. Though hampered by heavy drinking and later, drug addiction, during her peak period, she made a comeback and continued singing into the 1990s.

Born Anita Belle Colton in Chicago, she was raised largely by her mother, and entered her first marathon-dance contest while barely a teenager. She spent time on the road and occasionally back at home, later moving from dancing to singing at the contests. After bad experiences amid brief tenures with Benny Goodman and even Raymond Scott, O'Day earned a place in Gene Krupa's band in 1941. Several weeks later, Krupa also hired trumpeter Roy Eldridge, and the trio combined to become an effective force displayed on hits like "Let Me Off Uptown," "Boogie Blues" and "Just a Little Bit South of North Carolina." She spent a brief period away from Krupa with Woody Herman, but returned to the band, only to have it break up by 1943. After moving to Stan Kenton, she starred on Kenton's first big hit, 1944's "And Her Tears Flowed Like Wine." Another stint with Krupa presaged her solo debut in 1946, and with drummer John Poole as her long-time accompanist, she recorded a moderate hit one year later with the novelty "Hi Ho Trailus Boot Whip."

Her career really ignited after her first album (and the first LP ever released by Verve), 1955's Anita (also known as This Is Anita). Much more successful in the jazz world than she was in its pop equivalent, she performed at jazz festivals and jazz-oriented concerts, appearing with figures including Louis Armstrong, Thelonious Monk and George Shearing. Her performance at 1958's Newport Jazz Festival made her fame worldwide after being released on film titled Jazz on a Summer's Day.