Profile of American close harmony singing trio the Andrews Sisters, one of best-selling female vocal groups in the history of popular music. Collaborating with some of the great names of the swing era such as Glenn Miller and Tommy Dorsey, they also enjoyed a long and successful recording partnership with Bing Crosby. The film traces Patty, Maxene and LaVerne's journey from a poor Minneapolis background to international fame and includes archive footage of hits including Boogie Woogie Bugle Boy. Mary Wilson of the Supremes and British burlesque group the Puppini Sisters are also featured.