Do Bookspan and Yockey plan a whole series of gushy, premature, unnecessarily full-length biographies of conductors? Admittedly, Previn has had a more varied career (and a more headline-grabbing private life) than Zubin Mehta. But, as with Zubin (1978), the subject here seems too young and too minor a mid-career figure for such lumbering treatment (nearly 400 pages); and it seems a special pity that Previn--who is quoted in great chunks and obviously exerted substantial control over this project--didn't simply write some less-heavy handed memoirs of his own (like Gary Graffman's recent charmer, for instance). Certainly Previn's youth is the stuff of winning reminiscences: Berlin-born but raised (after 1930s flight from the Nazis) in Hollywood, piano-prodigy AndrÃ‰ wandered from his classical roots (a demanding musician-father) to become, starting at 15, a whiz-kid arranger/composer for the movies. . . while pursuing jazz-piano and modern music as sidelines. But despite many lively anecdotes (incompetent movie-composers, crude studio types, studies with Castelnuevo-Tedesco and Monteux), the brio of those early years is largely defused--by the authors' breathless-groupie prose (""His hair remained as dark, as fine, and as straight as it had been when he was a baby and he parted it now on the left"") and by their preachy dronings over Previn's longtime choice of lucrative Hollywood over serious music-making: ""Jack Previn simply stood by and watched his son skip merrily down a road which he felt certain would lead to ruin."" And though there's inherent drama in Previn's ""lamentably late discovery of himself and his true talents""--especially in his efforts to shake off the Hollywood image--little of it comes through here. Instead, there's masses of detail: on Previn's dispute-plagued conductorships in Houston and London; on tours and TV; on recording and repertoire (with defense of Previn's conducting style). His B'way score for Coco is barely mentioned, however, while there's little analysis throughout of his composing talent. And the private life--stormy marriage to songwriter Dory, affair/marriage/children with Mia Farrow--is touched on ever so discreetly, with Previn's personality coming across only in the (often self-deprecating) quotes. Some engaging material for Hollywood-music buffs, then, and scattered anecdotes for concert mavens--but otherwise strictly for hardcore, detail-hungry Previn fans.