Good words from Christopher, as usual.

My first thought was that this is more than a "one song" kind of thing.  Something may be bothering him totally unrelated to the music and for some unknown reason he's sublimating it through this song.

Possibility one is to follow Christopher's sage advice and approach it from a logical point of view.  In truth probably how I'd do it - unless the bass player is a close friend.  If he's a really, really close friend, value the friendship and drop the song.  There are a million others.

Possibility two is to table (but not drop!) the song and come back to it later.  Unless there are underlying issues (with bands, always a possibility), you may be able to put the song aside, maybe pick up a couple of tunes from bass dude, then come back later with this song.

Possibility three is that the guy is a pain in the a%& to deal with and you may be better off without him.

Of course, if he's a hired gun, pitch his butt out the door and find another.  Immediately.  He's being paid to do a job and he "ain't doin' it".

I've played all of these scenarios.  None of them are fun but of course it's part of being in a band.

Best luck and really cool that you're gigging!

Rumble