Alan Lomax, after a few drinks, would go after Bud and Travis at the Village Gate (I think it was that venue) cursing at them for bowdlerizing certain songs and being "commercial".
Al Grossman and Alan had a historic wrestling match over Dylan and the Butterfield Blues Band backup at the Newport Folk Festival. These Sumo folk wrestlers entertained the audience offstage.
There were those in the early Massachusetts and Philadelphia coffee houses when someone didn't do a song the "right" way were prone to raise their hands in the air as protest.
(They left out the scratch in the 78 recording by the Carter Family)