“Let There Be Peace On Earth” was composed in 1955 by husband-and-wife songwriters Sy Miller and Jill Jackson and introduced at a high school retreat. (They had those in the 50’s?)
(T)hese inspired young people brought the song with them and started sharing it. And, as though on wings, ‘Let There Be Peace on Earth’ began an amazing journey around the globe. It traveled first, of course, with the young campers back to their homes and schools, churches and clubs. Soon the circle started by the teenagers began to grow. Before long the song was being shared in all fifty states – at school graduations and at PTA meetings, at Christmas and Easter gatherings and as part of the celebration of Brotherhood Week. It was a theme for Veteran’s Day, Human Rights Day and United Nations Day. 4H Clubs and the United Auto Workers began singing it. So did the American Legion, the B’nai B’rith, the Kiwanis Clubs and CORE. It was taped, recorded, copied, printed in songbooks, and passed by word of mouth.
“Veni Sancte Spiritus” could be a chant, a Taize refrain, or any number of choral settings. The full text and brief history is here.