I distinctly remember old westerns where the triangle was used to inform outriders or those working in faraway parts a ranch that a meal was ready to be served. I know this is Hollywood, but a big old open triangle is a pretty easy and effective way to get sound to carry distances.
I see nothing strange in Bert's comment either, he was probably stating where he first hear the song, and nothing to do with authorship. Not sure that it would have mattered much to him and I don't think he was a man to use two or three words when one would do.