During a blues gig, a fill in bass player comes in a half step off... it was some Albert King song, and a long time ago
We all tell him the key it is in, but he keeps playing in the wrong key trying to tell us to switch (to his wrong key). We gave him the cut out signal, and I played LH bass on the tune.
So we ask him, what in the fuck were you doing on that song? He says "the original version is in A" (or whatever, I forget)
To which we reply, well that's cute and all, but we play the Albert King Version in Bb, which was on the CD and what we told you, you are sitting in with us and you therefore.. HAVE TO PLAY IN THE SAME KEY AS THE REST OF THE BAND.
He insisted we should all have changed keys because he apparently couldn't move his fingers up/down one fret and play the song..... I personally requested to fire the guy, which I did, and enjoyed.