POP MUSIC : *** 1/2 PJ HARVEY, “Dry”. <i> Indigo</i>

Great debut albums come in two forms: a) a fully defined work that expresses the artist’s vision so completely that it is, in effect, an instant classic (think Patti Smith’s “Horses” in 1975), or b) a seductive calling card that signals the arrival of an extraordinary new artist even if the album itself may not be the artist’s masterpiece (think Sinead O’Connor’s “The Lion and the Cobra” in 1987).

The intriguing thing about this debut from a British trio bearing the name of its lead singer-writer-guitarist is that it falls somewhere in between. There are moments in this work of unusual passion and power that make you think it may be the group’s “Horses,” but there are others that suggest it just may be an exciting warm-up to the group’s eventual equivalent of O’Connor’s 1990 gem, “I Do Not Want What I Haven’t Got.”

Either way, it’s a commanding exercise in which Polly Jean Harvey examines the sexual politics of troubled relationships with an anger, longing and confusion that is so intimate at times that the songs don’t seem so much material for the studio as outgrowths of a therapeutic need for personal cleansing. The intensity of her vocals and the daring of her lyrics aren’t PJ Harvey’s only strengths. The music--also supplied by bassist Stephen Vaughan and drummer Robert Ellis--offers a frequently intoxicating setting for Harvey’s tales. Despite occasional folk gentleness, the main thrust of the album is a mix of punk-accented insistence with blues-rock power-trio aggressiveness. The group plays the Whisky on Aug. 17.

Albums are rated on a scale of one star (poor) to four (excellent).