Dunno if the Scottish/Irish group who shall not be named is Capercaillie or not, but a year or so ago on their official website message board, an audience member from one of their British gigs complained of the band drinking on stage and the performance being bloody awful.And of course, all their "true" fans came out in defense of the band drinking on the job, or claiming they just had an off night.
There have been rumours of those problems for years about the band, though I've never known if they were true, or which members are said to have suffered the problems with drink. It sounded to me (from the message board) as if all or most band members were drinking on stage.
I think people who are, shall we say, not all that discerning when it comes to performance standards of their favorite musicians, have much higher tolerance of bad performances than those of us with higher standards who aren't enamoured of the musician/band doing the performing? Something to think about.
BTW, the person who posted the complaint about the gig was someone who claimed to be a newcomer to the band's music who had heard how fabulous the band is live. Might be food for thought for those professionals among you who think you sound better after a few, than you do without.