Photos by Klosty and a Festschrift contributed by Cunningham associates should constitute one of the more exciting dance books in a while. We haven't seen the pictures, but going by Klosty's Well-spoken ambivalence toward dance photography per se, they would have to be excellent or he wouldn't have published them. The text doesn't lend itself to quite that kind of judgment, but it is terrific if only for a forty-fathom plunge into the Cunningham milieu and aesthetic. The contributions are stylish indeed: Yvonne Rainer edges into the subject in third-person singular, conditional mood; Douglas Dunn interposes a series of koans, Rauschenberg files an absurdly touching statement of noncooperation--all testifying to a group esprit that may surprise readers who've heard of avant-gardists Cunningham and Cage and their stopwatches. For those who want to know about a major and still misconstrued artistic enterprise, this is the next best thing to participating. It is the book. Cage, Gordon Mumma, Carolyn Brown, Lincoln Kirsten and Edwin Denby are also represented.