Meandering in a Dreamscape : Ishiguro offers a complex, ambitious journey into the subconscious : THE UNCONSOLED, <i> By Kazuo Ishiguro (Alfred A. Knopf: $25; 535 pp.)</i>

Awake, we choose our life or our life chooses us, and we spend our days living out the consequences of the choice. Asleep and dreaming, we are haunted by all the choices we didn’t make and their exfoliating consequences. A kind of vital mainspring usually lets us give priority to our daytime acts and keep at bay the infinite alternatives, which, if admitted, would bring us to a clogged halt.

Any choice or action, however virtuous or prudent, will cause some pain, loss or dilapidation somewhere, even if it is only for what is not chosen or done. Daytime’s mainspring lets us lock down the possible guilt and regret for these things. At night the guilts, the insufficiencies, the terrors have nothing to check them but the twin facts that they are bodiless and that we are going to wake up.

Kazuo Ishiguro, in whose tersely sculpted novels of moral complexity and regret the night world looms faintly through the daylight (“The Remains of the Day,� “An Artist of the Floating World�), has now published a full-fledged nocturnal sprawl. It is not, of course, as huge and unrestrained as the most famous of dream novels: H.C. Earwicker’s 678-page sleep in “Finnegans Wake.� It lacks the vast web of conscious and unconscious digression, the portmanteau inclusiveness of just about everything its author knew, its quadrilingual puns, its global myth and its fearful difficulty.

For all that, “The Unconsoled� is complex and ambitious, and undeniably difficult. If not a literary Everest--oxygen! Sherpas! can we please go home!--it is at any rate a Mt. Washington, and formidable enough. It offers some remarkable views, and flowers that grow only in the thin air of heights. Whether they are worth the climb is beyond even the subjectivity of a review. At any rate, it is a book that is not given but has to be earned.

“The Unconsoled� is the life of a public man seen by the infrared light of his dreaming vulnerabilities. Ryder is a famous pianist but he could be any celebrated artist. The night doubts and demons that declare the unreality of his achievements presumably reflect something of what goes on between the much-honored Ishiguro and his own pillow.

Ryder finds himself the honored guest of a nameless European city, German or Swiss in feeling, and plunged into a profound moral and spiritual crisis. In this allegorical place such a crisis is declared in terms of music. The city’s tutelary composer, Christoff, an abstract modernist, is in disgrace; a movement is afoot to replace him with his predecessor, Brodsky, a once-revered romantic destroyed by his own debauchery and the winds of fashion.

A cabal made up of local politicians, a countess who is a leading art patron and the manager of the finest hotel is working to rehabilitate him. It is no mere musical matter; it means restoring the god to the abandoned civic temple. Either we succeed, one Brodsky supporter says, “or resign ourselves to being just another cold, lonely city.�

Thus Ryder’s effusive welcome. He is to play and speak in a few days’ time at a concert at which Brodsky is to demonstrate his regained mastery as a conductor. Ryder’s international prestige will put the seal on the enshrinement.

From the moment he checks into his hotel, everything goes askew, not as in life but as in a nightmare. He is told that he has a crowded schedule of vital meetings and events but never learns what it is. Everyone makes a claim on him he can’t refuse. The hotel manager wants him to spare a moment to examine a book of clippings collected by his wife, ostensibly a Ryder fan; her sanity, he implies, depends on it. The manager’s son, Stephen, a failed pianist who has taken up the instrument again, wants him to listen to a fearsomely difficult piece he will play at the Brodsky concert.

A hotel porter, Gustav, asks him to attend a meeting of the city’s hotel porters and work a reference to their devoted work into his concert talk. He also asks him to talk to Sophia, his daughter, who is in a deep depression. Sophia, it turns out--everything displaces and reassembles--is Ryder’s estranged wife. She wants him to abandon his peripatetic celebrity and make a home with her and their mournful little son, Boris. Boris wants Ryder to take him to their old apartment and reclaim a favorite toy.

The interruptions and demands escalate. Each time he sets out to fulfill one, he is waylaid by a new one. They become more and more insistent, and each is connected obscurely to a primal failure of his own. An old English schoolmate turns up indignant because he has not come to tea. An old English girlfriend accosts him on the tram where she is a ticket-taker and demands to know why he hasn’t turned up at a Ryder fan circle she has organized. He churns in all directions, never manages to get where he is going--typical of a nightmare--and all the while time is running out for him to practice for the concert. It is another typical nightmare, the performer’s, at finding himself onstage unprepared.

Not only do the claims, and Ryder’s sense of failure, multiply, but each proliferates in its own complexity and intensity. Different town factions make use of him. Everywhere he goes he is effusively welcomed, yet before long each welcome turns into recrimination or, still worse, invisibility. At the receptions in his honor nobody pays attention to him unless it is to allude to some past failure or present omission. When he finally gets to the meeting of his fan club, the women ignore him while talking excitedly of how they almost met him at one of his public appearances.

The succession of inexplicable claims, frustrations and cordialities that turn into recriminations, the frequent refusal of places to stay put, and a tendency for destinations to recede as Ryder approaches them--there is more than a suggestion of “Alice in Wonderland�--go on and on. Amid the dreamlike figures, some--Sophia, the forlorn Boris, the maddened Brodsky--acquire a sharp and vivid poignancy. The absurdities become more spectacular.

Ishiguro writes them with his characteristic grace and offbeat pungency. But for much of the book he strings them together, link by link, in a chain that seems to exist for itself, without binding anything up. It is a long meander whose picturesque curves grow wearisome after a while, for lack of a sense of a sea beyond. There is indeed such a sea. Ryder’s long nightmare operates a change in him; he has a ruefully chastened awakening at the end. It is an unexpectedly satisfying end but it needed to come sooner. The recounting of a dream is as quick to fade as the dream itself.