Something is off in the pre-chorus.
Not a train wreck. Just a half second where the chord under the vocal is not the chord on top of it. You run it again. Same thing.
Ten minutes later everybody has played their part alone and every part sounds right. The keys player is playing exactly what is on his page. Nobody is wrong. Somebody says it will be fine live, and you move on, because there are six more songs.
It is still there four months later.
Where the five versions come from
Nobody was careless. One person printed the first chart that came up in a search. One is reading a tab site on a phone. One worked it out by ear. One inherited a page from the guy who left, fixes and all. One learned it off the record in the car and is not reading anything.
Then somebody figures out the second chord in the pre-chorus is minor, not major. He is right. He pencils it in on his own page before the next count-in. The band did not learn anything. One page did.
Nobody hears it as a problem, because it is not a problem. It is one slightly wrong note inside five parts, and everybody is playing correctly according to the only page they can see. By next week nobody remembers which song it was.
A year of that across forty songs and you have five books that mostly agree.
The binder works
The old fix is a binder. One copy, it lives in the rehearsal space, and if you change something you change it there, in pencil, before you play it again.
I ran one for years. Two inches thick, sheet protectors, pencil through the rings. Inside that room it solves the whole thing. One copy means one version, and the argument about who is right takes four seconds. You go and look.
Its one problem is that it cannot be in two places. Sunday at home you are learning the new song off whatever is on your screen. On gig night it sits on one music stand and the other four are back on their own pages. A new player gets a stack of photocopies.
Pick a version and write it down
Before it is a filing problem, it is a band decision. The album version, the faster live one, or the one in the key your singer can still hold at the end of a three hour night? Second solo or not? Cold stop, or the fade nobody can end together?
You do not have to agree on the best version. Somebody has to say which one it is, and it goes at the top of the chart. Key, ending, which recording. Three lines. That is what stops you relitigating it every six weeks.
One librarian
The tidy answer is that everybody keeps their own chart up to date. That has never happened in a band and it is not going to start in yours. Four of you did not show up to do data entry.
Every band that has this solved has one person who cares about the charts more than the others. That is the librarian. Keep the version, take the corrections, be the place people go to look.
The other four owe two things, and neither one is typing. Stop keeping a private copy. And say the correction out loud instead of pencilling it in quietly. "I think that second one is minor" takes two seconds, and it is often the most useful thing anyone says all night.
Where BandBinder comes in
That deal is easier to keep when the shared copy is not in a room you are not in.
BandBinder gives the band one library. The person who keeps the charts fixes the chord once, and everyone who is online has it in seconds on whatever they are holding. The key and the ending travel with the song. Everyone else joins free with a band code and maintains nothing. If a second person wants to help, the manager can give them edit access. Everybody still gets their own private notes, because "watch the second verse" is usually only your problem.
One limit worth knowing: sync carries text, not files. A PDF stays on the device you added it to. Convert it to an editable chart and it travels with everything else.
The version your band plays is a real thing. It has a key, an ending, and a couple dozen small decisions that took months to make. It only exists if it exists in one place.