Long known for her smooth vocalizing and astute choice in material, Dianne Reeves' atmospheric performances for the soundtrack to the 2005 film Good Night, and Good Luck brought her greater recognition outside the jazz world. Three years later, When You Know finds her remaining true to her elegant, emotionally-nuanced sound. Produced by George Duke, the album captures the ambiance of a low-lit cabaret, favoring Reeves with intimate, acoustic-oriented arrangements. The singer’s caressing style — suggestive of Sarah Vaughan, but more understated — catches the subtle contours within tunes as diverse as the Temptations’ “Just My Imagination” and Michel Legrand’s “Windmills of Your Mind.” The highs and lows of love provide a unifying theme, allowing Reeve to float on waves of infatuation (“Lovin’ You,” “I’m in Love Again”), explore romantic regret (“Once I Loved”), and stir the ashes of old flames (“Social Call”). She’s especially beguiling on bittersweet numbers like “Midnight Sun.” The biggest kick of all is provided by “Today Will Be a Good Day,” a rousing Southern gospel-style number. Whether the mood is dreamy, downcast or celebratory, Reeves is nothing but impeccable here.