Marilyn Miller, that is--the beloved star of Broadway revues and 1920s musicals who died at age 37 in 1936. Harris (Gable and Lombard) follows Miller from her childhood, as the youngest member of a family vaudeville act (stage mother, tyrannical stepfather), to her discovery by Lee Shubert--which led to a solo turn in Broadway's Passing Show of 1914. (""Too early her career became her life."") Her sunny, dancing-singing appeal soon thereafter became one of Flo Ziegfeld's major attractions--in Sally, Sunny, and Rosalie; but though Flo obsessively doted on Marilyn, alternately feuding and fawning (""at times all but groveling at her tiny, size-one feet""), Harris scoffs at rumors of a Marilyn/Flo affair. (""There was no need for her to resort to sex as a bargaining tactic."") Indeed, Marilyn preferred younger men: after her brief, golden marriage to musical-comedy hero Frank Carter ended with Frank's auto-crash death, she went through assorted lovers--from syphilitic Jack Pickford (Mary's brother) to suave Jack Buchanan, from Jack Warner to Charles Lederer to ""handsome hunk"" Don Alvarado to chorus-boy Chet O'Brien, hubby #3. (As for her handpicked corps of male dancers, ""whether Marilyn was selecting them for sexual purposes as well is really impossible to know."") Her career started downhill about 1930, however--with a few Hollywood ups-and-downs, with less demand on B'way for Marilyn's unsophisticated musical-comedy style. And, despite a last hurrah in As Thousands Cheer, she ""simply lost the will to carry on"": after ""incompetent medical treatment"" (a botched sinus operation, improper drugs), she died from brain-swelling and toxically high fever. Throughout, Harris writes serviceably at best, with frequent lapses into fatuousness and vulgarity; his command of the Broadway/Hollywood-musical history involved often seems shaky; Marilyn herself, part child and part ""tough, foul-mouthed bitch,"" emerges neither in three dimensions nor very sympathetically. So this remains a show-biz bio of the most superficial, tacky sort--chiefly for devotees of 50-year-old gossip.