The Swingle Singers is a vocal group formed in 1962 Paris, France with Ward Swingle, Anne Germain, Jeanette Baucomont, and Jean Cussac. Christiane Legrand, the sister of composer Michel Legrand, was the lead soprano in the group. There were a total of 8 members in the group: two sopranos, two altos, two tenors, and two basses. The group, directed primarily by Ward Swingle (who once belonged to the famed French vocal group Les Double Six) began as session singers mainly doing background vocals for singers like Charles Aznavour and Edith Piaf. They did some jazz vocals for Michel Legrand, but when he left for Hollywood to do film scores, they were left with boring parts. Swingle cast about for something interesting to do and fell on Bach's Well-Tempered Klavier, which led to their hit album, Bach's Greatest Hits.