GERALD'S PARTY. By Robert Coover. Simon and Schuster/Linden. 316 pp. $17.95.

THE DUST JACKET invitation to attend Gerald's party arrives signed by some very striking names -- William Gass, Walter Abish, John Calvin Batchelor -- who belong in the experimental forefront of writing.

So, of course, does Robert Coover himself. He has put his flamboyant and original talents to a wide range of subjects, from baseball to Richard Nixon and the Rosenberg executions, and his writing extends from erotic fantasy to harsh political satire. Ever since his first powerful collection, Pricksongs & Descants, he has been preoccupied with the nature, magic and erotics of storytelling. Today there seems to be a major section of Brown University devoted to radical Gothic fiction. Like Coover himself, John Hawkes, to whomthis new novel is dedicated, teaches there. So does the British fantasy writer Angela Carter. All three produce a form of inventive fiction incorporating the esthetic obsessions of Edgar Allan Poe, the erotics of Sade and Genet, and the power to mix great psychological intensity with fictional play and parody.

What is parody? Tania, one of the guests at Gerald's party, tells us (she will be found not much later dead in the bathroom): "the intrusion of form, or death (she equated them), into life." Most of the guests at Gerald's party have strong esthetic faults; one of them offers Gerald his wife in exchange for a lesson on the nature of theater. Perhaps this is not surprising since they are part of an extraordinary esthetic thought themselves. They also have most of the other preoccupations of party-goers -- with food, drink, spectacular clothing, sex, urination, the blocked toilet upstairs, mistaken identities, murder. For the "intrusion of form or death . . . into life" comes very early (on page 12, in fact), when the body of Ros, actress, artist's model, porno film star and whore, is found stabbed on the living room carpet.

This brings Inspector Pardew, the philosophical detective who believes in the simultaneity of time and deduces that the murder occurred a half hour after he arrived, as well as some heavy cops, photographers, reporters, camera men, and an ever-expanding number of actors and film makers. Round the corpse, one of several the evening produces, Gerald's party goes on -- a chatter of voices, names, faces, faeces, overheard gags, endless storytelling, and a mounting curve of desire.

OUT OF IT ALL, Coover constructs a brilliant novel. Gerald's Party has been described as a mock murder mystery, but the drawing room detective story is only one of many art forms played with and parodied in this novel of strong, sustained invention and impersonation. The party becomes a theater, a film, a fairy tale, and an ever-accelerating trade over the space between the real and the fantastic. It is a field of desire always dissolving and reforming, a sequence of pratfalls and interrupted fornications, of extraordinary rituals: "Butcherblock Blues," "The Host's Hang-Up" and "Candid Coppers" are only some of the dramas staged for our delight.

Stories are seen as cunning deceptions; here they turn into every kind of tease, transfigured by the erotic laws of estrangement, deception and reversal. The mystery is solved, in perfunctory fashion; it really doesn't matter. The sexual pursuit by Gerald of Alison, the girl he dreams of, turns through pratfalls into disaster. What holds the reader is the manipulation of an amazing cast of ever-moving figures, the constant multiplying of styles and situations, and above all the unremitting babble of voices.

Gerald's Party is a very erotic and also very esthetic novel, a flamboyant display of the writer's repertory. The book has many Postmodern habits -- the characters are virturally characterless, they are voices, clothes and bodies constantly changing into other clothes and other bodies. There is clear philosophical dimension, to do with the relation of form to reality, as well as the relation between the storyteller's and the lover's habits of foreplay and combination. There are many deaths and various Gothic brutalities, all held within the frame of comedy.

The guests, those who survive, confess -- after 312 pages in the same house, on the same evening -- that they have had a very good time. You were probably out of town that night and missed it, which may have been wise. But you certainly should not miss what Gerald says about that infinitely memorable evening in the brilliant display that is Gerald's Party.