Sade doesn't chase trends. She doesn't tour unless there's a reason. She disappears for eight years and comes back with an album that sounds like a warm bath.

Helen Folasade Adu -- a Nigerian-British woman with a voice so smooth it could drop the temperature of a room by ten degrees. Smooth Operator. The Sweetest Taboo. No Ordinary Love. By Your Side.

She releases an album once a decade, doesn't do interviews, doesn't do gossip, and the records still sell millions because the quality never wavers. Her band -- Stuart Matthewman, Andrew Hale, Paul Spencer Denman -- built a sound that was part jazz, part soul, part something that didn't have a name and didn't need one.

Sade is the proof that you don't have to shout to be heard. You just have to mean it. Four decades. Six albums.

All of them essential. The coolest voice on earth, and she's never broken a sweat.