Do you remember “White Christmas” Concerts? I was in the orchestra during elementary school and we would play at different schools for their program. The children would bring cans of food wrapped in white tissue paper and put them under the tree, at the front of the auditorium. The school chorus would sing, some of the classes would have a short skit, and the orchestra would play as the children walked up.
My high school performed Handel’s Messiah every year. The solos, chorus and orchestra were all high school students. I don’t know how good we were, but the memories are great. I played cello and even now I “hear” the cello part when I hear the Messiah, whether on CD or in person.
In the 1950s and 1960s we weren’t very aware of non-Christian beliefs, and the children who would have been uncomfortable with the religious activities at school.