Come on now folks, it's usually only ONE SONG. I remember the time, On Mudcat Radio no less, when I was singing 'The Barley Mow' and a dear friend joined in with a version she'd learned somewhere else (from Seamus Kennedy I think), which had a BOOM, BOOM, BOOM in it.

Ok! it didn't fit with MY version but it certainly wasn't worth upsetting her about it. And like a true professional I carried on and didn't say a word. And I also learned that some people sing it differently.