Here's a quartet of pop/soul singers (including one newcomer) with instantly identifiable voices: DIONNE WARWICK -- "Friends" (Arista). Warwick's strongest album in years leads off with the year's most enjoyable Good Cause record, the Bacharach-Sager-penned "That's What Friends Are For," which manages to be both endlessly catchy and universally moving, and benefits AIDS research in the bargain. Warwick avoids the trap of inserting herself into trendy cookie- cutter arrangements, and comes up with an album full of winners, including the feather-light "Whisper in the Dark," Stevie Wonder's seductive slow-dancer "Moments Aren't Moments," and "Stronger Than Before," which seems to say it all for Warwick's career. GRACE JONES -- "Slave to the Rhythm" (Manhattan Island ST 53021). This strange disc calls itself "a biography," and though we don't learn too much about Amazon Grace, it's danceable and rhythmically intriguing. The album is basically eight overhauls of the inescapable single "Slave to the Rhythm" linked by interviews with Jones and stentorian narration from Paul Morley, who reads excerpts from Jones' former husband/art director Jean-Paul Goude, the creator of her menacing, androgynous, flattop image. Producers Trevor Horn and S.J. Lipson construct a tidal wave of sound, welding electro-rock and James Bond movie themes, with an underpinning of go-go -- the "Big Beat Colossus" rhythm section includes D.C.'s own Little Beats and Shorty Tim. GRACE JONES -- "Island Life" (Manhattan Island). Here Jones has progressed from just a presence to a real Voice. This retrospective of her career charts her voyage from her disco days (she does Piaf's "La Vie en Rose" a la disco, and makes it work) to her groundbreaking mating of reggae and new wave (represented here by "Pull Up to the Bumper" and "My Jamaican Guy"). The album also includes high-energy remixes of her distinctive covers of the Pretenders' "Private Life" and Roxy Music's "Love Is the Drug," and still another version of "Slave to the Rhythm." STEPHANIE MILLS -- "Stephanie Mills" (MCA 5669). Stephanie Mills must have watched Whitney Houston's skyrocketing debut with interest. The keyword there was diversity, and in a calculated move for a Big Album, Mills mixes up the formats from whispery ballads to chunky stompers, with help from can't-miss songwriters and producers Rod Temperton and George Duke. Having left her "Dorothy" image behind long ago with "The Wiz," Mills makes a solid play for the dance floor, coiling her infinitely flexible 45 rpm voice around the soul scorcher "Stand Back" and other electrofunk numbers in a steamier vein, such as "Automatic Passion" and "Rising Desire. TAKA BOOM -- "Middle of the Night" (Mirage 7 90290-1). Newcomer Taka Boom sounds strangely familiar. That siren wail, even the name remind us of someone. Could it be her big sister Chaka Khan? Yes, but with her sturdy singing on "Middle of the Night," Boom proves that though the pipes may be hereditary, she doesn't need to imitate her sister (who makes a distinctive background appearance on two tracks). Boom's deep, throaty voice works out against glossy big beat settings on such risque numbers as "Pleasure Unit" and "Butter Me Up." But this debut could stand some diversity -- all the songs were written and arranged by Billy Rush, who, having found a winner with the title track, merely alters the words and tempo of that winning melody for the seven others.