Madonna may be built up as pop music's reigning sex siren, but that's mostly a matter of her fondness for lingerie over blouses. On the whole, her music manages to avoid the sort of sexual references currently raising eyebrows. Those truly interested in tuneful titillation would do far better by investing in the latest recordings by Olivia Newton-John and Sheena Easton, a pop pair who, despite their good girl images, have a definite predilection for racy material.

All it takes is a glance at the back cover of "Soul Kiss" (MCA 6151) to see just how much Newton-John wants to distance herself from the fresh-faced wholesomeness of her "Have You Never Been Mellow" days. The photo shows the singer admiring herself in a mirror, wearing riding boots, skintight riding pants and a strategically positioned scarf. Looking at the picture, it's hard not to wonder what exactly she plans to do with the riding crop she's holding behind her back.

This is, after all, a distinctly kinky album. "Culture Shock," for instance, starts out as a lament over a love triangle, but the solution the singer offers is hardly run of the mill: "I know it's unconventional but why can't the three of us live together?"

That's not to say this album spends all its time in the gutter. "Queen of the Publication," after all, isn't about centerfolds, but the nasty nosiness engendered by personality journalism. But there is a certain sexual spin to the material here. "Overnight Observation" is a funny number about a physician who wants to play doctor, while "You Were Great, How Was I" chronicles the end of a one-hour affair.

Newton-John gets away with a lot of suggestiveness because the songs are given the same slick understatement that has long set the standard for her sound. "Moth to a Flame" finds her screaming the last chorus, but on the whole, her delivery is as polite as ever, while the rhythm tracks emphasize restraint above all. "Soul Kiss" is so staid, in fact, it's tempting to imagine that the sex stuff was slipped in to keep the listeners from nodding off.

Sheena Easton's "Do You" (EMI America SJ 1713) suffers from no such somnolence. Produced by Nile Rodgers, who also handled "Like a Virgin" and a dozen other recent chart toppers, it's bright and perky, underlaid with funk and carefully latticed with hooks. As a piece of pop product, it's hard to fault.

Still, there's something strangely anonymous about Easton's singing. Take "Magic of Love": A typical Rodgers tune, it matches a lilting melodic line to a lithe groove with the cool confidence of his hits with Chic. Trouble is, Easton doesn't convey any more personality than Chic's almost faceless singers did. In the end, "Magic of Love," like so much on this album, sounds more like it belongs to the producer than the performer.

Naturally, that drains much of the life from this album, which is a shame, because there is an otherwise wonderful balance between the seductive and the coy in the songs here. It isn't the music's fault, either. Aside from a cover of Martha Reeves' hit "Jimmy Mack," an ill-advised indulgence showing how soulful Easton isn't, most of the material is powered by the chattering rhythm guitar and insistent dance beat that have become Rodgers' trademark, lending a physicality to the music that is perfect for a song as sweetly sexual as "Do It for Your Love."

Sadly, when Easton sings in that song, "Do you feel the same connection?" the listener is likely to answer "no." There's no grit, no passion to her performance, and that leaves any semblance of sensuality flat. As a result, a song like "Can't Wait Till Tomorrow" sounds strangely patient, with Easton singing the chorus as if she were wondering what was on TV that night. This is modern passion? If so, the Parents Music Resource Center has nothing to worry about.