The Sweetest Taboo singer is Sade, a four-letter name. Sade is a British singer, songwriter, and actress who has been active since the 1980s. She is best known for her soulful, smooth sound and her hit singles such as 'Smooth Operator' and 'The Sweetest Taboo'. Her music has been praised for its sophisticated blend of jazz, soul, funk, and soft rock. She has won numerous awards, including two Grammy Awards, and has sold over 75 million records worldwide.