John Kirkpatrick (1905–91) was an American pianist and scholar who was instrumental in promoting the music of the American composer Charles Ives. He is probably best known for his performances of the Concord Sonata; he gave the New York premiere of the work at Town Hall in 1939. He was also asked to catalog the manuscripts of the composer that had been given to the Yale Music Library in 1956. A Temporary Mimeographed Catalogue of the Music Manuscripts and Related Materials of Charles Edward Ives, 1874–1954 was published in 1960.

John Kirkpatrick joined the faculty of Yale University in 1968. Both he and Ralph Kirkpatrick were teaching at Yale at that time, but they had established a friendship as early as the 1940s. They were not related, as far as they knew, but they clearly had a warm friendship. Because they were both keyboard players with the same last name, they regularly received correspondence meant for the other Kirkpatrick. Some letters had sections that clearly related to John while other sections clearly related to Ralph. Both men responded with good humor and passed on the letters to each other.

October 2, 1943

Dear Ralph,

I am sending you under separate cover an editing of the Chromatic Fantasy and Fugue that I did this summer. It started out just as a copy to have something reliable to give pupils (I didn't know then that Kalmus had reprinted Bischoff), but it ended up as something considerably more thorough than originally intended. I thought you'd be amused to see it, even though the whole interpretative side of it has the twentieth-century piano in mind. If you happen to have time to look at it, I'd appreciate gratefully any comments or criticisms that occur to you… .

How are things with you? I wish we could get down to NY [a] week from Tuesday to hear your “Concert at Nine.” We'll be thinking of you though.