Just venting, not really a situation where I need advice to manage, but we'll see where it goes.
So my bread-and-butter gig is a cover band, for the last seven or eight years or so. Like a lot of cover bands, we play a variety of stuff, classic rock, pop, a little country, and so on. We don't try to make a big deal out of being somehow "different" from your normal bar band; we just try to do it really well. ONLY songs that go over, no personal vanity picks, and we keep the set list moving rapidly so there's no dead air. It works.
The band is built around a singer who has her strengths and weaknesses. She has a pretty good voice, not quite as good of an ear, and is musically largely untrained. But especially, she's very much a native of the local bar scene, the venues know her and like her, she has lots of friends who come to see her. Bookings come in pretty steadily and gigs are generally decently-paid and -attended. It's a good gig.
We had to replace our original guitarist a couple of years ago and there weren't very plentiful pickings for the range of music we play. Pretty much only one guy who auditioned was up to it. He also has his strengths and weaknesses. He has good chops; doesn't blast excessive volume; and has a real sense of how to arrange set lists to keep the flow going that's our signature. He's also very aware of being the only treble/chordal instrument in the group and thinks a lot about how to fill the space or arrange his part when the song originally had keys or a second guitar. That's important (we're power trio + singer), but not always on the mark; some songs he applies too much gain when it should be clean because he's afraid the single clean guitar will sound "wimpy," or he'll try to keep up a rhythm pattern while also playing a lead. It can wind up overbusy. Sometimes he'll vary the chord, using an inversion or something to change it up. A lot of the time his ideas work; sometimes I'll hear a clam or he'll get off the beat. The drummer is solid as a rock and I'm pretty good at holding my part down, so given the lack of options we found, I'm content to tune the clams out and let him work it out.
The singer, though, tends to pick at him, and really laid into it at last night's rehearsal. She keeps asking if he's out of tune or in the wrong key. He isn't, and she barely knows what those terms really mean (she's the least musically trained of the four of us, remember). What it usually is, is that he varied the chord in some way, brought out an interesting harmony or voicing, and she got thrown off because she wasn't hearing what she was expecting. She's also been sitting in with another band from time to time over the last few months. So this time she wouldn't let it go; she says that singing with the other band is "easy," nothing throws her off, while at our gigs lately she's been having a hard time and feeling like things don't sit right. She backpedaled after saying that, I think realizing it sounded like a threat to quit, and said she had been feeling this way before she started singing with them. But it's out there.
I try to stay out of this. My philosophy is not to tell another musician how to play their instrument unless I know exactly what it is they need to change and how to do it (I sometimes find myself counting out loud along to a recording to show him, or her, what beat a note falls on). If I were him, I wouldn't feel great about coming into rehearsal to get raked over the coals about my playing by someone who doesn't know what I'm trying to do. I do sometimes encourage him to trust his clean tones more, to lay back and leave some space in the song, and to remember to count to four. But I really don't want him to feel like we're piling on.
So there we are. I guess I'm trying to gauge whether I should let it blow over, let the two of them hash it out, take a side, or what. I've been playing with these people a while and we're friendly, not tight friends, and I don't play with them because the songs are my own personal "heart" music. It's that I like to entertain, I like to get people dancing, plus it's nice to get paid, and this band has been a great vehicle for that. I'd really rather not see it implode over this.