"By conventional definitions 'shimrod' only the words and a tune make the 'tradition' traditional. So everything else is up for grabs, arrangement, instrumentation, idiom, style, presentation."

Give us a flavour of what you're hoping for, 'glueman'. I reckon that if you're so insistent that what's on offer is, in some way, wanting, then you have a responsibility to offer concrete alternatives (not just 'wishy-washy' abstractions).

I'm told that Kirsty MacColl was very talented - possibly she was. She didn't do a lot for me - just another 1980s pop singer as far as I could tell.

I did meet her "old man" on several occasions. As a callow 1960s teenager, already sick of 'pop pap', MacColl's singing, and the songs that he sang, came as a huge revelation to me. Not only that but he was accessible and eager to share his knowledge and his ideas. He gave me the confidence to get up and sing - something that I've been doing ever since.

I would dispute that MacColl's approach to singing traditional songs was "specious and arbitrary" (I suspect that you mean 'not to your taste'). He had a deep knowledge and appreciation of traditional singers and singing. His theories on the singing of trad. songs were convincing and profound.
As for "resistant to vying modes", I can't comment because I don't know what it means!