I've just joined a new covers band. They've been gigging their set for a few years. I come on board and sort out my own transcriptions of the set only to discover during rehearsals that the keyboard player is playing the wrong chord now and again. He's 99% spot on, but is clearly (to my ears) playing the wrong chords in certain parts of certain songs. They're not mistakes - it's how he's transcribed them himself and the way he's been gigging them for years.
Now, they're not hideously out, like a semitone or anything, and I'm not sure many in the audience would even notice, but I noticed during rehearsals. I sent him my transcriptions and asked him to note any differences down in the way they've always played them (mainly for format differences etc) and he's "corrected" a few by changing what I know are the correct chords (from the notation / audio analysis etc) into his incorrect versions.
Now - I don't want to piss him off - I'm the new boy, but it does grate my ears when hits the wrong chord.
I've tried to be as diplomatic as possible in my exchanges with him, pointing out that, for example, "Sorry mate, but the second chord in verse 3 is definitely a Bb major" and included a short clip of the original, slowed down, with the vocals stripped out, so he can hear for himself that what I'm saying is correct. The response I've had is basically along the lines of 'you play what you want mate, I'm going to carry on the way we've always done it'. I'll be surprised if he's even listened to the clips I sent.
Yes, I'm a bit anal about these things, but I'm surprised his musical ear can't hear the error - or - more importantly, that the original chords sound better than what he's playing.
So.... what would you do; play the correct chords loudly so it drowns out his wrong ones or just kiss ass and play the wrong chords along with him ? :-)
Question everything - with the exception of the Earth being a spheroid and the moon landings.