This is the third one of Mr. DeLillo's one-of-a-kind novels in as many years -- metamyths dealing with the unlovely face of America phrased this time (the last was a football player) around a rock-'n-roll artist "in endland" who retires to a "cold as a penny" room on Great Jones Street in lower Manhattan. There the "apocalyptic crotch" -- his real name is Bucky Wunderlick -- secludes himself in "prayerful fatigue" leaving his group to disintegrate while his public permits all kind of conjecture (was he murdered, maimed, etc.) not only to keep him alive but to extend the legend. But privacy (the real desideratum?) is not altogether his as he's visited by his girl (she will be killed), others from the group, and some assorted pitchmen and entrepreneurs connected with something called the Happy Valley Commune which almost has an ultimate drug -- a downer -- in their avid hands. Mr. DeLillo, also one of the great spielers, keeps so many ideas up in the air at the same time that you're not sure which one is supposed to come down in a stabilized state ("America. The whole big thing. Popcorn and killerdrugs." ? or Wunderlick's retreat from it -- "Evil is movement toward void"?). But in any case there is the same brinksmanship, drastic verve and undercutting lip which give these concepts and abstractions (these include the characters) a surreal sense of life just as it faces extinction.