Following up on Early Music Sources’ excellent video on vibrato from a few weeks ago, here’s an article that explores the topic in more detail (especially about historic organs)!
Vibrato or no vibrato?
I generally live somewhere between the “straight-tone only” and “vibrato always” worlds, believing that the best singers do both, according to the needs and styles of the repertoire being performed. But what do the treatises say? Early Music Sources does an excellent job exploring the options (with special shout-outs to organ treatises and my perennial fav, Praetorius)!