Whatever fame Kirkpatrick enjoys is due mostly to the January night in 1939 when he gave the New York premiere of Charles Ives's Second Piano Sonata, the so-called Concord Sonata, at Town Hall in Manhattan. This four-movement work includes musical portraits of American Transcendentalists Ralph Waldo Emerson, Nathaniel Hawthorne, the Alcott Family, and Henry David Thoreau. That 1939 concert—arguably among the most important of the century for American concert music—precipitated the discovery of Ives and his music by a wider audience, while establishing Kirkpatrick as a major figure in the performance of contemporary American music. His relationship with the Concord Sonata shows in vivid detail the tension between his dual careers as a pianist and an editor.

Kirkpatrick had an ambivalent relationship with the sonata. On the one hand, he wanted to—indeed, was obligated to—deliver a fixed impression of the Concord in any given concert. This was a task for which he prepared diligently throughout his life, even to the point of carefully writing down notes to himself for certain performances. For example, figure 4.1 shows a chart of relearnings that Kirkpatrick made for the Concord, where he meticulously notated the changes he had made in February 1953, January 1957, and June 1961; a page following the one reproduced here also shows what he was playing in 1981, shortly before the stroke that ended his performing career.