*Philosophy of Advanced Music* (1941), 106, MSS No. 29A, Series XI.A. Miscellaneous Writings by Others, Box 191, Folder 1, Virgil Thomson Papers, Yale Music Library.
*Philosophy of Advanced Music* (1941), 106, MSS No. 29A, Series XI.A. Miscellaneous Writings by Others, Box 191, Folder 1, Virgil Thomson Papers, Yale Music Library.