The Boswell Sisters were a close harmony singing group, consisting of sisters Martha Boswell (June 9, 1905 -- July 2, 1958), Connee Boswell (original name Connie) (December 3, 1907 -- October 11, 1976), and Helvetia "Vet" Boswell (May 20, 1911 -- November 12, 1988), noted for intricate harmonies and rhythmic experimentation. They attained national prominence in the USA in the 1930s.