The Andrews Sisters were an American close harmony singing group of the swing and boogie-woogie eras. The group consisted of three sisters: LaVerne Sophia, Maxene Anglyn, and Patricia Marie. They achieved great success in the 1940s with their hits 'Boogie Woogie Bugle Boy' and 'DON't Sit Under the Apple Tree'. The Andrews Sisters are often referred to as a threesome or TRIO, which are both words that can be used to describe a group of three people.