I did a little playing tonight, going outside with the Bell Banjo. It started at 50% RH, and as it grew darker, reached 68%. At about 65%, I could feel the pitch squirm a little bit, but no big issue. It got a little tubbier sounding then too, but was good. The skeeters came out then, so I came in. Anyway, having great fun watching conditions relative to the instrument and it's behavior.