I enjoyed reading this essay on Randall Thompson and The Testament of Freedom by Honey Meconi, who is both the inaugural Arthur Satz Professor at the University of Rochester and Professor of Musicology at the Eastman School of Music (as well as a former member of the Tanglewood Festival Chorus).
In addition to summarizing the received critical wisdom about the work (“popular rather than original”), Meconi’s essay calls out a point that I missed: that the longevity of the work may in part be due to Thompson’s completing its symphonic orchestration in time for the Boston Symphony to use it in their memorial concert for Franklin D. Roosevelt at Carnegie Hall. She also notes the irony of the original TTBB setting, due to the fact that UVa’s undergraduate program was not coeducational at the time (though, as we know, the woman’s Madrigal Singers group, made of students from the University’s other schools, would perform with the Virginia Glee Club several times during the war years).
Anyway, the essay is worth a read, as are the other essays on her site, which she collectively calls “The Choral Singer’s Companion.”