First attracted attention on the nightclub and cabaret scene for her bluesy jazz intonations and later enjoyed considerable success on the Broadway and London stages. Brown made her breakthrough with a London staging of "The Threepenny Opera" in 1956 and is perhaps best remembered for originating the role of Nancy in the smash London and Broadway hit, "Oliver!", intorducing the now standard "As Long As He Needs Me". (She lost out to Shani Wallis when Carol Reed adapted the musical to film in 1968.)
Although Brown began acting in films in 1957, the 1970s marked her busiest period. Typically cast in blowsy, bawdy roles, she enlivened such features as "The Fixer" (1968), "Tales That Witness Madness" (1973) and "The Seven Per-Cent Solution" (1976) and also appeared in the PBS miniseries "Shoulder to Shoulder" (1975) and "The Rebel" (1976). Late in life Brown returned to the London stage to perform in "42nd Street" and "Greek", and to Broadway in the title role of "Roza" (based on the 1977 film "Madame Rosa") and the 1989 revival of "Threepenny Opera" starring Sting. She also lent her distinctively husky voice to the animated TV programs "Rick Moranis in Gravedale High" and the short-lived "Fish Police" before her sudden death at age 58.