A graduate student from Amsterdam emailed me with a request for Allan Kaprow's review of Kenneth Koch's The Construction of Boston. A portion of his review was published in Floating Bear #30. The handwritten draft of the essay is in the Kaprow archive at the Getty.
I post it here as an example of the mimeo mag as critical journal. You think of mimeo as a vehicle for poetry but the medium also provides access to some of the most up-to-the-minute criticism and accounts of contemporary poetry, art, theater, literature and architecture that is available. Much of it I would suspect has slipped through the cracks of the various anthologies, collecteds and selecteds.
Here is the Scott Wheeler's setting of the Happening (initially performed for one night at the Maidman Theatre on 42nd Street in New York City in 1962) to music and Koch's libretto for context: