Those who revere the cast album of A Chorus Line will definitely want to settle down with this mostly readable, essentially good-hearted saga of Broadway-musical dancers (""gypsies"")--which boasts only the thinnest, most clichÃ‰d plot and characters but does have more convincing showbiz/lifestyle atmosphere than most such workups (Garson Kanin's totally unlifelike Smash, for instance). Lipton merely follows one B'way-bound musical from auditions through its try-out week in Philadelphia--concentrating on heroine Carin Bradley, a 19-year-old ballet student who gets dragged to the audition by new chum Diane (the tough, aging, crying-behind-the-wisecracks stereotype to the hilt). Carin's secret, however, is that she's diabetic--like dancers Joan McCracken and Carol Haney, who died young--and this medical-crisis material adds just enough extra grab to maintain a modicum of tension. As for the rest, it's strictly by the numbers: Carin has a journalist boyfriend who's jealous of her career, angry about her on-the-road affair with the company stud; Carin and Diane have an aging, campy-homosexual, unemployed dancer-roommate who'll commit suicide while the girls are in Philly (his funeral is the novel's tacky-maudlin low point); Carin is chosen to be a featured dancer and must rehearse all night to prepare for her big moment; there's a Gypsy-style stage-mother-monster who pimps for her daughter; etc. But Lipton is relatively tasteful in recycling and updating all the backstage familiars--sex but nothing too kinky, vulgarity but nothing too gross. And his details are impressively authentic--from the dancers' muscles (though the prose here gets awfully artsy) to the varied reactions when there's a pathetic closing in Philly (the neophyte book-writer weeps while veteran gypsies instantly call their agents). Don't look for depth, originality, or grownup characters: the cutesy, narrow, puerile, soppy showfolk sensibility is projected all too well. But this chatty, episodic, musical-comedy melodrama is going to be trÃ¨s big on Manhattan's Upper West Side--and wherever else the stagestruck-dancer is an indestructible ikon.