Being jazzy has become very hip in British pop circles. It isn't so much that jazz itself has caught on in any big way; rather, the flavor of jazz has been subsumed into English rock the same way that rockabilly was absorbed a few seasons ago. While this hasn't exactly shaken the music industry to its foundations, it has brought a handful of exceptional vocalists to light, among them Sade Adu, Tracey Thorn, Ben Watt and Carmel McCourt.

Of these four, Sade Adu -- or simply Sade (pronounced Shar-DAY) -- will make the greatest impression on American ears. True, it doesn't hurt that the Nigerian-born singer is visually impressive as well, but where her exotic good looks merely intrigue, the smoldering passion of her singing draws the listener irresistibly. As demonstrated on her debut album, "Diamond Life" (Portrait BFR 39581), Sade has star quality to spare.

With a voice that seems a cross between the unadorned purity of Joni Mitchell and Joan Armatrading's rich resonance, Sade is by no means a belter. Instead, she insinuates her voice into melodies the way Nina Simone would, conveying a sense of emotional warmth, yet sticking close enough to tuneful simplicity that the listener isn't made to feel an intruder. Granted, it's an awfully fine line to walk, and Sade manages it with such casual ease that her success almost seems more luck than craft, but the end is an album of delightfully expressive pop.

"Hang On to Your Love," Sade's first American single, is a perfect example. The setting her band concocts is jazzy but direct, suggesting a Steely Dan workout on the "Billie Jean" groove, and its cosmopolitan cool makes Sade's breathy delivery all the more affecting. Better still, there's a sense of quiet desperation underlying her performance that perfectly illuminates the song's chorus: "In heaven's name, why are you walking away?/Hang on to your love." Between the two, it manages to work convincingly both as a dance record and a love song, a feat too infrequently managed on the pop charts these days.

Sade's ability to put these songs across with conviction provides the album with its strongest moments. In other hands, "Sally," with its almost maudlin concern for the plight of the hard-working and under-rewarded, might have been an irritation; here, it seems to resonate with compassion. Similarly, "When Am I Going to Make a Living" adds little to the we'll-be-famous-if-we-try optimism of "Fame" and countless imitations, but the fire Sade puts into the repeated chorus, "We're hungry but we won't give in," is enough to convince the most jaded listener.

Where Sade regularly applies heat to make her point, Tracey Thorn and Ben Watt, better known as Everything But the Girl, are resolutely cool. Nothing wrong with that, of course, especially for those who can make cool a positive quality.

But Thorn and Watt have partly copied their vision of cool, in this case from Astrud and Joao Gilberto. Watt doesn't quite manage the subtle color Joao Gilberto is justly famous for, though he does get the phrasing right. Thorn, though, caresses her phrases with the same constrained passion that fills Astrud Gilberto's best work, and it's that quality of her singing that most commends "Everything But the Girl."

The album starts off, true to influences, with a delightful samba, "Each and Every One," which makes the most of the sweetness in Thorn's singing without seeming at all overt; and this strategy carries through to "Laugh You Out of the House," "Fascination" and "Mine." But the duo declined to stick religiously with this formula and as a result, "Everything But the Girl" turns up some unexpected influences. A few are unnecessary, among them the blunt folk-rock treatment given "Native Land." But most are surprisingly apt, from the Doors overtones of "Frost and Fire" (note how Watts' guitar solo coyly quotes from "Light My Fire") to the Horace Silver-styled "Crabwalk."

Everything But the Girl is successful in giving latitude to its sources in large part because it understands and respects them. Carmel, on the other hand, operates under the impression that its favorite performance styles take precedence over everything. Thus, the trio assembled around singer Carmel McCourt reduces everything from "Stormy Weather" to "Tracks of My Tears" to the same interpretation. As a result, the group's lamentable debut, "The Drum Is Everything" (Warner Brothers 25083-1), sounds like a single, dreary shade of blue.

It would be foolish to deny that McCourt has a powerful voice; the yelps and hollers she unleashes are strong and sure. But where other, better-directed singers might apply such a voice to gospel- or soul-inflected music, McCourt has gone deep into rural blues and Pentecostal gospel singing. Rather than understand those styles in context, though, McCourt emerged with only a set of vocal mannerisms. As a result, she ends up a parody of the very styles she would emulate; worse, in attempting to be bluesier-than-thou, she demonstrates a curious disrespect for her sources, one that seems likely to preclude any real growth as an artist.