It's the voice of Judy Garland, back from the dead. And it's coming from all the speakers in Gerald Clarke's big house in Bridgehampton. ''No more 'Over the Rainbow' for me,'' Garland says in a throaty drawl. ''I've grown up. Those days are over.'' Garland made those tapes during the mid-60's for a possible autobiography, said Mr. Clarke, whose own biography of her, ''Get Happy: The Life of Judy Garland,'' is being published by Random House this month.

''Here's where she's spaced out,'' said Mr. Clarke, listening intently. Mr. Clarke had bought the tapes, he said, from one of the many Garland fans among whom they circulate. ''I am an angry lady. I'm a lady who is angry,'' Garland says. ''I've been insulted, humiliated.'' Garland, who died in 1969, was angry at her agent, David Begelman, who she thought was stealing money from her, and at the press who recorded every time she stumbled. ''The world has turned against her,'' Mr. Clarke said.

There have already been at least four full-scale biographies of Judy Garland, plus several memoirs by those who knew her. Indeed, Garland's life is a well-known soap opera. There was the unhappy childhood, the overdoses, suicide attempts, exploitative relationships with men, five husbands, the tantrums. And her seemingly erratic mothering of her children, Lorna and Joey Luft and Liza Minnelli. But for those who don't already know enough about Garland, there is more in Mr. Clarke's book.

During his research Mr. Clarke stumbled on what could only be called pure gold for a biographer. He said he found an unpublished manuscript of Garland's 68-page autobiography in the Random House archives at Columbia University. It was begun by Ms. Garland with her friend Fred Finklehoffe in 1960, when ''she was ill with hepatitis,'' said Mr. Clarke.