A piano tuner told me, and this was the explanation: "It is possible that the G# will be the first to get sluggish when humid as the flange is probably tighter than average."....
Are you sure he/she was talking generally, rather than specifically about your piano? Like, maybe there was something about that particular flange (which would be my guess)....
It certainly sounds to me as though the tuner were referring to the particular piano in question, rather than to all pianos in general....
Off the subject, but......I can't help it....

This is a great example of where I think the rule about using the subjunctive in such a situation is a poor idea -- and I don't do it. Good thing I'm not still in school, because I might flunk.

I think that actually
most people who know about the subjunctive and generally use it properly violate the rule in such a context, but (as far as I know) it is nevertheless considered wrong.
What do I mean by "such a context"?
A context where the stated situation is very possibly
actual. I reserve the subjunctive for where it's just being imagined, or at most highly unlikely. I think the subjunctive sounds
strange when the stated situation is true or very possibly true, but as far as I know, the rule doesn't care.
The rule needs to be changed.
Pass it on.
