Richard Kostelanetz, who edited The New American Arts …, has also written or edited several other books on literature and the arts. In [The Theatre of Mixed Means] he defines "mixed means" as various noises and sights—people shuffling along the street, electronic beams, even the noise of many butterflies being released from a bag—which constitute a special kind of theater when these accompany some sort of dramatic happening, no matter where it may be presented, in a street, field, hall, or theater…. The mixed means Mr. Kostelanetz describes are often used, or are happening, at the same time as the plot (if there is one), apparently distracting the audience. The modern mind seems to need to be splintered in many artistic directions at once in order to feel involved. To an old theatergoer who wants to find some meaning in a dramatic action that has a beginning, middle, and end, mixed means may not seem to be theatre at all, but another form of art. This question is among the many Mr. Kostelanetz discusses with practitioners of this new art: composers, dancers, poets, sculptors, and others…. For those with open minds about what "theater" means, this book is instructive and interesting. (pp. 1497-98)
Marquerite McAneny, in a review of "The Theatre of Mixed Means: An Introduction to Happenings, Kinetic Environments and Other Mixed Means Performances," in Library Journal (reprinted from Library Journal, April 1, 1968; published by R. R. Bowker Co. (a Xerox company); copyright © 1968 by Xerox Corporation), Vol. 93, No. 7, April 1, 1968, pp. 1497-98.