I think that in terms of backing vocals in the space that includes weekend player bands, two ways (Captain Obvious here) band members can differ is in level of desire to sing (some don't want to sing, some are willing, and some really want to) and ability (some flat out can't sing, some can but may take more effort to learn and memorize harmony parts, and others can both sing and pick up harmonies naturally). You have what you have and you work with it. What I've thought more about is how different combinations of desire and ability determine where successes and difficulties occur and determine how much effort goes into achieving or dealing with them. I see there being combinations that are negative, neutral and positive. Someone who is capable but reluctant for example, takes effort in coaxing possibly...positive result/higher effort. Someone less capable but who really wants to sing should be able to improve with practice...positive result/effort largely on them. Someone who can't sing, recognizes that and doesn't try is at least net neutral, positive if they're not needed because it's settled out of the gate/no effort.
What I'm curious about is experiences with the situation where a band member wants to sing...badly, but just never reaches the level where their singing is consistently a benefit? They put in effort, the band puts in effort, but it just doesn't work.
We have someone who regardless of effort, practice, drilling harmonies at rehearsal just never gets to the point of any real consistency, overall. He still frequently sings off key, has trouble finding his note at gigs even after getting them in rehearsing, and his voice simply doesn't blend particularly well (there is a quality that seems inherent in it that sounds like someone casually singing along with music in the shower or their car and the music is suddenly taken away or like a random audience member got a hold of one of a mic and is in the mix). His voice is naturally baritone and he says he can't sing falsetto at all "Nothing comes out!" which is limiting to say the least for rock and pop backing vocals...all those great baritone parts.
He'll often decide on the fly to double another line, almost always the lead (often an octave down) because melody lines are usually the most familiar. When unison isn't really unison it just creates crap. We've worked up things based on his being okay with certain parts...like "Sing here but not here," but during gigs he'll sometimes add vocals anyway because he honestly seems to think it sounds good...
Which is a big challenge here because he doesn't seem to be able to hear the problems in real-time or recordings. Playing back a recording with something egregious, which we thought might help, doesn't seem to make it click for him...most people don't like hearing the sound of their own recorded voice whether good or bad singing let along hearing what is actually bad. I don't think there's any ego or malice involved. I genuinely think he believes it sounds good which doesn't make sense because, not that he has perfect pitch or anything, he can clearly hear instrument pitch and tone just fine.
I know this is TB and the obvious answer is "Fire him and the drummer", "Just tell him his singing is crap and take his mic away", or "I wouldn't stay in a band that let that continue"...as much as I'd love to have the band decision (that he would happily go along with) be to just not allow him a mic, that kind of thing just isn't realistic. There are friendships involved, some going back to childhood, and the fact is that there are also songs where he does have his parts down and they add something...but that creates the next thing which comes from him having a mic and not having his itch scratched by what he does well enough, which is drawing the line himself...he's become a habitual line stepper.
As I've thought through this, I'm guessing that the band member who wants badly to sing but can't AND can't hear that they can't is probably a rarity versus other combinations...but I'm still curious if others actually do deal with the same thing...and anything that might have worked. Brutal and blunt solutions obviously can and do work in theory and reality but aren't on the table for us. Success in channeling that enthusiasm or to keep someone from improvising extra vocals without any butt-hurt? A pipe-dream? It seems possible that this just one of those situations where the only actual solutions come at the cost of some damage?
Creating a dedicated member role in the band for a sound engineer has been discussed and could incidentally help some for this in simply having control in burying certain vocals, but it wouldn't really be viable for this band overall and there a multiple standing annual gigs (where this matters the most) where I just don't see how we'd be able to use our engineer if we had one.
