Cuddled up on blankets under a moonlit sky, a lot of folks at Wolf Trap Saturday night roused only long enough to applaud Michael Franks for providing a romantic soundtrack for a late summer's eve.

As sensuous as his band's light Caribbean and South American rhythms were, however, the music had a high snooze quotient, or as one listener was overheard putting it, it was "mellow, mellow, mellow." Back when that term was more in use than it is today, at least as it applies to music, Franks carved out a niche for himself in pop-jazz by combining clever (and sometimes cute) wordplay with insinuating melodies and rustling percussion. He hasn't budged much since, and while the new cuts from his album "Blue Pacific" compared favorably with "One Bad Habit" and other older hits, the limitations of Franks's rather colorless voice and the sameness of his material eventually took their toll.

In the opening set, the talented guitarist Larry Carlton described some of his music as "happy jazz," the sort that produces lots of smiles in the audience. Happy it may have been, but even when Carlton turned to what he called "dark jazz" or blues, the results were often more impressive on a technical than an emotional level. Voices of the Soviet Union