Schafer, R. Murray. “Charles Ives and Perspective.” Ear Clearing: Notes for an Experimental Music Course, 31-36. Don Mills, Ontario: BMI Canada Limited, 1967.
Peterson, Thomas Elliott. “The Music of Carl Ruggles in Relation to the 20th Century.” In The Music of Carl Ruggles. Ph.D. diss., University of Washington, 1967.
Meyer, Leonard B. Music, the Arts, and Ideas: Patterns and Predic-tions in Twentieth -Century Culture, 200. Chicago, IL: University of Chicago Press, 1967.