The subgenre once called ''trip-hop'' -- sullen divas mooning over spacey hip-hop tracks -- has largely been absorbed into current singer-songwriter pop, with the phat beats either buried or gone: see Dido, Jem, or even the recent set by the style's queen, Beth Gibbons of Portishead. Lamb (singer Louise Rhodes and beat master Andy Barlow) began as a Portishead with drum-and-bass grooves, and on their latest they remain beautifully true to form, with tricky rhythms and weepy strings pushed into the foreground. And the writing has only improved; while the new songs take odd approaches, they often bloom unlikely hooks. BEWARE THE QUIET ONES On ''Till the Clouds Clear,'' Rhodes' parched blues purr escalates into a chilling coyote wail. Who knew?