They may not be singing (all that much better) when you play the organ. It is my experience that people who can't (won't is the correct word) sing without instrumental accompaniment is that they aren't really singing. They are just mumbling along while the organ gives them the impression that they are singing. I recently subbed at a parish at which I had to tell the 'cantor' not to sing the hymns and ordinary into the microphone. She said with an air of certitude that 'they won't sing unless I do'. What, in fact, they were doing was listening to her sing while they mumbled along. When I finally got her to step back from the microphone, I discovered (with little surprise) that I could hear 'them' singing quite well. There are people who will gladly be babied as long as you will baby them; and, consequently, they never grow up.
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