dave the gnome , no,
not ruining folk music but ruining the enjoyment of someone who wishes to hear folk music, it maybe a competently perfomed version of rave on, but if the audience member went to hear willy of the winesbury, he she might have had a ruined evening.
you were running a club and assumed that everyone wants to hear buddy holly, it is rather like advertising martin carthy and you substitute him with andy caven. a good way to piss off your audience.[ andy caven performed buddy holly songs well] but that is not what most people had come expecting