No other demographic group in pop music has been kept more powerless through the years than female rhythm and blues singers. The attitude of the male-dominated R&B field has traditionally been: "Keep your weight down, keep your hair done up, and leave the song writing, arranging and producing to us." Admittedly, some great music has emerged through this system -- from the Supremes and Patti LaBelle through Anita Baker -- but more often one feels one is hearing a male perception filtered through a female voice rather than an undiluted female experience.

Fortunately, the situation has been improving in recent years as more and more R&B women assert themselves. Singers such as Janet Jackson, Aretha Franklin, Deniece Williams, Teena Marie, Sheila E., Angela Winbush, Brenda Russell, Meli'sa Morgan and Lesette Wilson have been writing and producing their own records -- and sometimes playing on them as well. As this trend strengthens, R&B will reflect a female perspective far better than it ever has.

Angela Winbush: 'Sharp'

The breakthrough record for this movement could very well be "Sharp" (Mercury 832 733-1 Q1), an album "written, produced, arranged and performed by Angela L. Winbush for A. Winbush Productions Inc." If that credit recalls the back of a Prince album, the music inside recalls Luther Vandross: a mesmerizing mix of state-of-the-art dance tracks with old-fashioned, from-the-heart soul singing.

The album is divided into a "Slammin' Side" of hot dance tracks and a "Quiet Storm" side of sultry ballads. The dance side kicks off with the hit single "Sharp," which is built atop a pushing/pulling rhythm track that is one-third James Brown rhythm guitar, one-third Larry Graham slap bass and one-third Prince drum machine, all arranged and played by Winbush. What really makes the song work, though, are the multilayered vocals that smack and resound like percussion instruments as they sassily deliver the message that her man had better be sharp if he wants to stay with her.

"Sensual Lover" and "Run to Me" are undisguised imitations of Marvin Gaye's "Sexual Healing" and Prince's "U Got the Look," respectively, but they only prove how well Winbush can hold her own in that company -- both as a singer and as a studio whiz. She possesses a spectacular voice that can shake the rafters like a gospel soloist's one moment and then curl itself around a ballad like a jazz singer's the next. More importantly, she knows how to use it; she can wail and purr with pure eroticism and never lose her precise sense of melody and harmony.

Even in her highest swoon and in her softest purr, there's a muscular toughness in Winbush's voice and lyrics to indicate that she's very much her own woman. She pursues love wholeheartedly but with the insistence that her own needs be met. When a man leaves her, she doesn't wallow in self-pity but tells the fool that "You Had a Good Girl (And You Lost Her)." A major step forward from her work as half of Rene & Angela, Winbush's debut solo record ranks with Stevie Wonder's "Characters" as the best R&B album of 1987.

Brenda Russell: 'Get Here'

Brenda Russell's "Get Here" (A&M SP 5178) is not the milestone that "Sharp" is, but it's the best showcase yet for this overlooked singer-songwriter. Like Luther Vandross or Valerie Simpson, Russell was a successful songwriter (for Donna Summer, Roberta Flack and Earth, Wind & Fire) and background singer (for Elton John, Barbra Streisand and Michael Franks) before breaking through as an artist. This is her fifth solo album, but it is the first she has produced herself and thus the first to show off her skills to best advantage.

As her re'sume' might suggest, Russell's instincts are solidly commercial, and "Get Here" is mainstream pop-soul at its finest. Russell fits together catchy radio hooks, dance beats and lyric twists like an expert pop jeweler. The title ballad, for example, marries a yearning, romantic melody to a plea that her lover travel by swinging vines, hot air balloon, magic carpet or horseback -- "just get here if you can."

"Gravity" plays on the idea of a force field that pulls two lovers back together; the tugging rhythm arrangement reminds one of Earth, Wind & Fire. The two best songs are "Piano in the Dark" and "Le Restaurant," which create a powerful sense of scene and unsatisfied love against music that recalls Roberta Flack with its hints of cabaret jazz beneath the pop-soul surface.

Russell has a strong, pleasing voice that can handle any task from belted dance number to whispery ballad. For all her admirable craftsmanship, however, she never establishes her own distinct personality. It's as if she spent so many years making demo tapes that could fit any singer that she lost any sense of her own style.

Meli'sa Morgan: 'Good Love'

Meli'sa Morgan parlayed her stunning looks and strong voice into Top Ten success with her 1986 debut album, "Do Me Baby," despite her rather awkward way with a song. Her follow-up album, "Good Love" (Capitol CLT-46943), marks a big step forward musically, but it still leaves her far short of Winbush and Russell. Morgan's powerful soprano gives the songs a convincing jolt of electricity, but she displays absolutely no sense of subtlety or style.

Morgan and her longtime keyboardist Lesette Wilson wrote and produced five of the nine tracks, but their work is rather pedestrian. Morgan sounds more comfortable on her own songs, but the compositions fall back on the most obvious musical and lyrical formulas. Ironically, the album's hit single is Paul Laurence Jones' "If You Can Do It: I Can Too," which finds Morgan belting out the quasi-feminist message that a woman can mess around just like a man.