Doesn't anybody smile on CD covers anymore? Has pessimism, or at least the appearance of gloom and doom, become a prerequisite for musical success? Do we feel that a smiling person just can't be taken seriously? Pop musicians, it seems, must be brooding and confrontational, or at least serious and slightly disturbed.

The cover images for Wet Wet Wet's latest album,10, conform somewhat humorously to this latter images, shamelessly contradicting the lively spirit of the music they introduce. The Scottish foursome look mad and bad, sporting black threads and dour expressions. But their songs are upbeat melodies, ranging from the catchy to the soothing, the brisk to the beautiful.

True, the Wets don't deliver bubbling effusions of unconditional happiness. In fact, the majority of the songs on 10address the everpopular themes of lost love, abused love, tragic love, and confused love. But the music is optimistic. The rhythms are cheerful, and the lyrics are hopeful. This is not a vision of disillusioned youth.

So why the long faces? The members of Wet Wet Wet don't need to hide their achievement. The Glaswegian group have enjoyed remarkable success in the UK, celebrating the coincidence of their tenth album and their tenth year, hence 10. And 10 capably combines the beautifully melodic with the infectiously upbeat. The album is mellow, but not sleepy--a charming combination of pop and a touch of big band jazz.

From the catchy opening track, "Strange," to the lovely, graceful "Theme From Ten," 10 offers a host of variations on its slow, melodic style. "Strange" is lively and engaging, more funky than the album's other tracks, resting on the sounds of the trumpet and saxophone and on a distinctive percussion foundation. "Theme From Ten," on the other hand, sounds very much like a serene soundtrack, with guitar chords bubbling to the surface in harmonious succession. One might envision a little girl frolicking in a meadow, picking wildflowers, in a series of exuberant freeze-frames--to opening credits, of course.

A couple of the best songs on 10, "The Only Sounds" and "If I Never See You Again," slow and elegant yet distinctly alive, arose from Wet Wet Wet's first collaboration with the celebrated songwriting team of Graham Lyle and Terry Britten. The strengths of these songs are their melodies, smooth and irresistible, taking Wet Wet Wet's relationship with the slow song a step beyond what they achieved with their number one single "Love is All Around," from the soundtrack of Four Weddings and a Funeral.

10's two covers, "Yesterday" and "Beyond the Sea," sung in the styles of the originals, fit the style of the album well and are sung beautifully. While the Wets don't add much to the originals, they do the songs justice, which is more than can be said for many adaptations of originally superior tunes.

The album does have its low points, however. "Lonely Girl" doesn't maintain its momentum as well as the other tracks on the album--it's the kind of song that you almost want to sing along with and you almost want to dance to, but in the end you just don't. "I Want You," on the other hand, is strictly a slow song; but unlike "The Only Sounds," for example, its melody lacks the spirited quality that prevents most of the album's slow songs from slipping into dreamland.

In addition, 10 ends rather abruptly. The final track, "It Hurts," standing alone, is an enjoyable tune; and with reference only to the song, its ending works well. But as the finishing piece of a CD such as 10, "It Hurts" is rather problematic. Perhaps the song was chosen to conclude the album due to its subject matter. The tune refers to the pain of endings, finishing by repeating the refrain, "It hurts to say it's over/It's sad to say it's gone." But this lyrical significance is tenuous at best, and on a CD of melodies, the final musical feeling is far more important than coincidental words of conclusion. The quick ending of "It Hurts" leaves 10 with a lack of satisfying closure. The album ends; it doesn't conclude, leaving the experience of the CD slightly cheapened and incomplete.

But for the most part, 10 is lively, lovely, and fun. The Wets have produced a charming collection of melodic pieces ranging from the actively slow to the gently energetic--a welcome addition to their successful collection of delightful melodies.