These are the known borrowings by Ives of music by other composers. These borrowings have been identified by J. Peter Burkholder in All Made of Tunes: Charles Ives and the Uses of Musical Borrowing (New Haven, CT: Yale University Press, 1995) and by Clayton Henderson in The Charles Ives Tunebook, 2nd ed. (Bloomington: Indiana University Press, 2008).
The “Songs” listing encompasses several categories defined separately in Henderson: “Patriotic Songs,” “Popular Songs,” and “College Music,” and some songs that he groups in “Classical Music.” The “Instrumental Pieces” listing presents a number of fiddle tunes.