Melba: THE VOICE OF AUSTRALIA by Therese Radic (Macmillan: $28; 214 pp., illustrated) : Beverly: AN AUTOBIOGRAPHY by Beverly Sills and Lawrence Linderman (Bantam: $19.95; 356 pp., illustrated)

Diva literature is a category all its own, and it is better than fiction. “Such Sweet Compulsion,” “Men, Women and Tenors,” “My Way,” “Wings of Song,”--the titles alone tell us a lot about the sopranos who wrote them (Geraldine Farrar, Frances Alda, Lilli Lehmann, Lotte Lehmann, respectively).

Recent autobiographies are holding up the side. Not that long ago, Marilyn Horne was confiding to her readers about her lonely Christmas Eve discovery that she had crabs. A new biography of Nellie Melba reveals, for the first time, the cause of her diva death--the great Australian soprano perished of an infected face lift. (Therese Radic gives no documentation for this claim, but a footnote points to a taped interview with an anonymous source who cannot be named for another 20 years). And now we have Beverly Sills admitting that she does hold grudges--now the Red Queen is in a position to cry, “Off with their heads!”

The disappointing thing about these two new books is that they tell us so little about the art of these singers, which is presumably what awakened our interest in them in the first place. Neither “Melba”--the whole world knew her by her last name--nor “Beverly”--America is on a first-name basis with her--is much good, and the Sills book in fact inflicts considerable damage on an image it took many careful years to develop.

Radic, who teaches music at the University of Melbourne, has published her Melba scrapbook. There are some amusing photographs (Melba meets the original Rin Tin Tin), and in the margins of her text, Radic reprints anecdotes, letters and commentary from other sources that are almost invariably more interesting than anything she herself has to say. Radic devotes pages on end to the history of musical education in Australia, for example, before she gets round to Melba’s contribution to it, so it’s more fun to read the margins. Asked to create Isolde for Paris, Melba writes to her teacher, Mathilde Marchesi, “Do you think it will be injurious to my lovely voice?” The pianist Percy Grainger writes, “My father was on the same ship with (Melba). Think what she said, quite publicly moreover, at the table when someone offered her jelly which was a little un-firm. ‘No thanks, there are two things I like stiff, and jelly’s one of them.’ ” But for a full description of Melba’s miraculous voice and the technique that sustained it for more than 40 years, for a discussion of her interpretive powers and an analysis of her hours of recordings, you will have to look to the margins, and where they direct you.

“Beverly” is Sills’ second autobiography. She wrote the first, “Bubbles,” 10 years ago to forestall a book by a writer who was snooping around her family; it was an entertaining collage of her best talk-show stories. At the time, she promised a “real” book later, but “Beverly” isn’t it.

Melba was a careful guardian of her own reputation. The ghostwriter of her memoirs (“Melodies and Memories”) was sharply instructed to make her appear “generous” in all that she said. Sills has not been as fortunate in her associate, longtime Playboy interviewer Lawrence Linderman. Linderman has not pushed Sills beyond anecdote and easy generalities when it comes to the artistic questions about which she presumably has a lot to say, nor has he questioned her closely about the circumstances and compromises of American musical life, which she is in a unique position to analyze.

Instead, the circumstances of celebrity biography require her to discuss other celebrities, even when she has little to say about them, rather than some of the people who played a more prominent role in her career. “(Carol Burnett) is a delightful, soft-spoken woman with striking good looks. On television, this great comic actress always liked to make faces and mug a lot, so people got the idea she was kind of homely, but Carol’s really beautiful.” And Linderman has done absolutely nothing to protect Sills from her less-attractive impulses and traits of character.

The familiar fun-loving big-hearted Sills is of course here to admire. The early part of her career, the rise from talent shows and singing commercials to international stardom, with years of toiling away in bus-and-truck and regional opera in between, is a great American success story, and Sills relates it with spirit. She is moving and straightforward in presenting her family tragedies, its hard-won victories, and the love that sustained them through everything. The pages about her directorship of the New York City Opera don’t have much to say about artistic questions and decisions, but they accurately portray the crushing financial problems most arts organizations face, and you have to admire Sills’ success in lightening those burdens for the City Opera.

But in too much of the discussion of her public life, the diva turns querulous, defensive, and even nasty. She gloriously rose above the worst that life can offer anyone, but the petty annoyances of her operative career lead her into flurries of petty vindictiveness. She is generous to everyone who was ever loyal to her, who ever did exactly what she wanted--to Tito Capobianco whose productions were devoted to making her look as good as possible--but decisively and derisively ungenerous to anyone who ever got in her way. She goes after Rolf Liebermann because he was small-minded enough to hold her remarks about one of his operas against her when he became head of the Paris Opera, but when it comes to forgiving and forgetting, Sills is no more admirable herself.

She doesn’t stop with dismissive remarks or unflattering stories, but goes on to assign unpleasant motives to those who disagreed with her--or even to those who have arrived independently at the same conclusions. She herself admits that during her first seasons as director of the New York City Opera, the company was putting out “an artistically shoddy product.” If the most respected critic in the business said so, Sills believes, it was because she had replaced his sister as the company’s director of public relations. Sills is not joking when she says she and her friend Arlene Francis share the same personality trait--”Neither of us could stand it if everybody didn’t love us.”

At the end of her book, Sills hints that her resignation from the City Opera may be forthcoming and that she may embark on a third career. One wishes her well, and hopes that writing a worthier book will be part of her new life, for she has too much to say to settle for a product as shoddy as “Beverly” as her legacy.