Could it be that you're maybe being over-analytical here? If the repertoire is those well-loved, familiar songs, it's not going to be real shocking to any of them...

Once I was at a fiddle contest, and the emcee--you know the type, real cornball all the way--called the winners of the "oldest couple" contest up on stage. They he sang "You're too old to cut the mustard" to the gent and "The old grey mare she ain't what she used to be" for the lady.

Now that even I found a tad disrespectful. Talk about getting personal!

Guy's name was Cletus something-or-other...
W-O