Sometimes the most obvious points are easy to miss. For years, I had passively puzzled why singers in the 16th century and before are always shown in paintings and drawings to be crowded together around a single piece of music. Why are they not shown with folders, the way carolers in Victorian paintings are shown?
Okay, to zero in on the question is to provide the answer. Sheet music was scarce -- no presses, photocopiers etc. -- and the music is often big, as shown in the painting that appears on the new issue of Sacred Music. They had only one copy, so singers would learn to read from surprising distances.
This makes me laugh because these days, all directors know that singers hate it when they have to share music with anyone! But perhaps standing so close together has the advantage of helping everyone blend! Can you imagine the pecking-order culture that would emerge under such conditions?
My apologies to everyone to whom this was already obvious (which it probably was to everyone but me).