I'VE NEVER BEEN to Pittsburgh, and I've never seen Homewood, the gallant black neighborhood which is the setting of Sent for You Yesterday. But Homewood is a part of my world now, like Faulkner's Yoknapatawpha County.

I can almost see Cassina Way, where the poor blacks just up from the South huddled four or five to a room, and Tioga Court, where the upper crust of Homewood lived, and Homewood Avenue, where old man Indovina kept his store until a holdup man shot him, the corner of Frankstown and Homewood, just across from the Bucket of Blood, where the proud, despairing black men sat on boxes and waited for white people to drive up and offer them day-labor jobs.

I compare John Edgar Wideman's fictional territory with Yoknapatawpha by design: Wideman has a fluent command of the American language, written and spoken, and a fierce, loving vision of the people he writes about. Like Faulkner's, Wideman's prose fiction is vivid and demanding--shuttling unpredictably between places, narrators and times, dwelling for a paragraph on the surface of things, then sneaking a key event into a clause that springs on the reader like a booby trap. The 200-odd pages of Sent for You Yesterday took me two weeks to read and reread; I'm still not sure I have gotten everything I could from Wideman's story of the Frenches and the Tates and a half-century of their lives in Homewood.

Summarizing that story is no easy task. Should I begin with Albert Wilkes, shot down at the Tate's piano by corrupt white policemen, or with Lucy Tate and Carl French, storybook lovers and drug addicts, or with the mysterious, tragic Brother Tate, who appeared one day "from the moon or wherever people with no color and no names came from" and carried on Wilkes' music until pain and grief killed him, too? As Wideman tells us, this story does not begin and end; it unfolds and refolds, like "one of those tissue paper and stick fans from Murphy's Five and Dime all folded so you can't see what's inside, but you roll off the gumband and spread the sticks and it's sunsets and rainbows and peacock tails."

In fact, as in Faulkner's Absalom, Absalom, much of Sent for You Yesterday is told by narrators who did not see the events they are describing. "I am not born yet," Doot, Carl's nephew, tells us as he retells a scene from his uncle's early life. Like Faulkner, Wideman focuses not on the events themselves but on their effects on those who come after, the burden and liberation they impart to future generations, who must remember and retell them and seek in them the meaning of their own lives and the keys to their futures.

"Past lives live in us, through us, (he explains). Each of us harbors the spirits of people who walked the earth before we did, and those spirits depend on us for continuing existence, just as we depend on their presence to live our lives to the fullest."

In fact, these past lives are the only salvation for the people of Homewood, hemmed in by poverty and the impersonal malice of white society, "the ones whose lily- white hands held Homewood like a lemon and squeezed pennies out drop by drop and every drop bitter as tears, sour as sweat when you work all day and ain't got nothing to show for it." Homewood fights back with music and with memories. An Albert Wilkes or a Brother Tate, who can play the blues "so fine you said Thank Jesus a day early," appears once a generation, fights and loses; but each new generation rises to fight again. "The old Homewood people taught me you don't have to give up," says Lucy Tate; she passes this message on to Doot, who is a young man in the 1970s when the story ends, "on my own feet. . . . Learning to stand, to walk, learning to dance."

John Edgar Wideman heard the stories of Homewood during his childhood there. Born in Washington in 1941, he grew up in Pittsburgh and went to Penn on a basketball scholarship, winning both a slot in the Big Five hall of fame and a Rhodes scholarship. He has taught English at the University of Wyoming since 1974.

Wideman writes the way Albert Wilkes played; Sent for You Yesterday is a book to be savored, read slowly and read again. That's exciting enough; but in publishing terms, Wideman's work is a hopeful phenomenon for another reason. Avon has published Sent for You Yesterday--and two of Wideman's previous books, Damballa and Hiding Place--in original mass-market paperback editions.

It's an experiment by the writer and the publisher. Avon wants to establish the paperback original as a vehicle for new serious fiction; Wideman wants to reach readers, black and white, who can't spend $14.95 for a novel.

Reviewers and readers who value covers instead of contents are missing a significant book, and a trend. Someday all new novels will be published this way, and those that survive a decade or so later will reappear in hard covers. At any rate, I predict, that's what will happen to Sent for You Yesterday.