IT'S BEEN more than 10 years since Stephanie Mills emerged as a sweet-voiced Broadway star in "The Wiz." But even though she's traded the stage for the charts and the dance floor, that sense of drama remains in her unique approach to a song.

Mills opens the solid first side of her new LP "If I Were Your Woman" with the hit "I Feel Good All Over," a slow-burning ballad with a gospel-like choir that breaks the singer out of her dance-identified mold.

Anyone who covers a Gladys Knight tune does so at her own risk, but Mills proves more than equal to the challenge on the title track, applying new rhythms and phrasing and adding a seductive note to her feline voice. With its stuttering, grumbling synths and sequencers, "(You're Puttin') A Rush on Me" is a timely anthem of sexual self-control, and Mills suggests a graceful way out of a come-on: "But I'd like to know you better -- maybe next time."

Mills wrote or co-wrote the four comparatively forgettable songs on side two. "Sweet Lady," a mistress' lament, gets the story across but is short on melody and structure, and Mills' singing style is a bit baroque for the stripped-down street rhythm of "Can't Change My Ways."

The Whispers called their 16th album "Just Gets Better With Time," and they live up to the title. The 20-year-old harmony group is known mainly for slick soul ballads, and they score once more with melodic murmurs like "In the Mood" and the title track. And on beat-conscious uptempo numbers like "Special F/X" and "No Pain, No Gain," the Whispers prove they can rise to a shout, too.

STEPHANIE MILLS --

"If I Were Your Woman" (MCA 5996).

THE WHISPERS --

"Just Gets Better With Time" (Solar 72554). Both appearing Saturday at DAR Constitution Hall.