On a bad day, Joan Armatrading has more substance and soul than most rockers this side of Van Morrison. On a good day, Armatrading can give even Morrison a run for his blue money. Yet her flirtation with unsuitable production styles has begun to weaken the impact of her work.

After three albums of straightforward rock & roll, Armatrading has returned to the quirky kind of material that characterized her Seventies LPs, records that won her a devoted following. Then and now, she tosses aside the usual pop geometry of verse-chorusbridge, writing wonderful songs full of unexpected twists and turns. Unlike the arrangements on her earlier, Glyn Johns-produced albums, those on Secret Secrets betray, rather than serve, the structure of her melodies.

The rocker "Moves," for example, builds to a chorus that feebly echoes Bruce Springsteen's "Born in the U.S.A." And on "Temptation," Armatrading is undone by Mike Howlett's bag-of-tricks production: a horn section blares; a chunky guitar fades in and out; chimes peal; and strings saw away with an anguished intensity reminiscent of early Elton John. In pursuit of a pop hit, Armatrading and Howlett have apparently chosen to disguise the subtleties and eccentricities that made her work special in the past.

The most successful tracks are those on which the arrangements are least intrusive. The moving "Love by You" finds Armatrading accompanied only by Joe Jackson's sympathetic piano. "Strange" focuses on the singer's voice, an instrument more evocative than all the horns in Tijuana: when Armatrading makes an unexpected vocal ascent, her shift from power to vulnerability is heartbreaking.

Although Joan Armatrading is one of rock's great talents, she may never reach the wider audience she deserves if she continues to receive the kind of unsympathetic treatment evident on Secret Secrets. A word of advice to her next producer: Don't mess with those amazing songs. (RS 448)

BILL FLANAGAN