Within a familiar housewife's-lib framework, first-novelist Kashner rummages about through the guilts and fears of a 33-year-old woman and comes up with some bright recognitions--although they're unfortunately dimmed by a lulling cast of shallow supporting characters. Beth Clahr, wife of Richard--who calls her ""Baby"" and is as thick as brick--and mother of two pre-teeners, looks forward to her Wednesdays in Manhattan: she sings in a chorus and is studying sight-reading at the Marines School of Music. Furthermore, the chorus offers, along with challenging music, a fellow chorister and would-be lover named Gideon. And, most challenging of all, Mannes' faculty now urges Beth to enroll for a degree and serious voice training, which could lead to a soloist's career. But Beth seems locked into a cage of home obligations--not just the matter of being on call (to produce a fox-tail for Michael's play or deal with Randy's volatile moods) but also a corrosive fear for her children's safety, a need to be present and needed. The pull of her music study, Richard's insensitivity, the kids, the dogged Ladies of the League, the neighborhood Good Mommies who serve home-baked instead of Twinkles, and then the terminal illness of friend Jessie--all these crowd Beth, and she roots about for a small private space where she can tune out a world that's become too noisy. Increasingly she takes to her bed--she's beginning to be a bit flaky about perfect sheets--and the family starts learning to manage without her, a situation even more frightening than being needed too much: in slipping out of her role, is she endangering her children? And before she brings it all together, Beth must confront death (Jessie's, her mother's long ago, an aborted baby) and must recognize the limited power to bind or save others. Finally, then, with a determination to loosen--but not break--home ties, Beth, after her shriving bed rest, plans for school and a career. Kashner may stumble in fleshing out her cast--the men are cardboard, the supporting women are stereotypes--but there are some fetching kitchen-P.T.A. perceptions here. . . and some valiantly pursued home truths.