up to my ears in academics, i came upon the words of John Maguire, a northern irish farmer:

"The way the air can be turned and lowered and ris [sic], that was a very good thing in our young days. they'd tell you about how much a man could turn a song, like raise it and lower, and the way their voices could change a lot. there was some very good singers you know about this country. if you knowed music you'd know he had an air to start with, and if you were fond of music you'll know it. then a man that can use the words and pronounce them right, when he has a good air, he's a good singer."

ca. 1971 _Come Day, Go Day, God Send Sunday_ by John Maguire, published under the name of his collator, Robin Morton