When I mentioned to timprov that this was something I was trying to figure out, he took me through a few things that were incredibly simple and worked. So yay for success! We have done a few things lately like having me sing a song for him while he tried to figure out the chords for it, since he can both play the chords and hear the notes now.
But it was sad to me because I realized that I had been actively taught wrong. Not just not actively taught right, but some of the things that my old church choir director, who was a very dear person, had explicitly taught us with teaching songs I can reproduce to this very day...were wrong. Were directly, exactly, the opposite of what you want to do when you're singing to get a good pure tone with volume control. What I was taught to do with my head and neck while singing was just exactly opposite. And now that I know it, I can look at footage of singers and go, "Uh, yah. They are all doing the opposite of what she taught us to."
Several of my experiences with this sort of thing were things I was aware of at the time and resented. I was, for example, taught that the Germans sunk the Lithuania, and that the Pentagon was on the Acropolis. I was taught that all electron shells after the first one contain eight electrons. And I fussed and fumed and fulminated against the teachers who taught me these things. But with this choir director...I'm just sad. I have fond memories of her. I can't dislike her. And yet she taught me a thing that has made an activity I enjoy more difficult than it had to be, with worse results, for literally thirty years, and I am only 33. I don't really know what to do about that except to be sad and baffled.