From the moment they emerged into the brash pop jungle of the mid-1980s, London soul band Sade stood apart, with jazz-infused romance and a kind of quiet, sophisticated languor as their signature. Part of this, naturally, is the room-stilling presence of eponymous frontwoman, songwriter and Drake tattoo (true story) Helen Folasade Adu: a British-Nigerian former fashion student whose poised, breathy delivery possesses a piercing quality whether it is aboard a twanging, island-scented groove (“Sweetest Taboo”) or wreathed in come-hither, moonlit blasts of saxophone (“Your Love Is King”). But, across the sporadic, considered releases that have followed 1985 debut Diamond Life, Adu’s bandmates Paul Denman, Andrew Hale and Stuart Matthewman have been just as integral in adding new riptides of complexity to Sade’s trademark, seductive smoothness. “Immigrant” packs a snapping, trip hop beat and presciently tolerant message, while “The Big Unknown” (recorded for Steve McQueen’s 2018 film Widows) suggests sinuous, spine-tingling darkness will be king on a forthcoming, long-promised, seventh record.