I’ve been to quite a few different towns recently, and had to do a bit of pitch-correction on some of them.
What does this mean?
We usually tune pianos to standard pitch, “A440”.
But if the piano is flat or sharp, we first need to do a pitch-raise or pitch-lowering, and afterwards a fine-tuning.
With all the rain lately, the wood of the soundboard and bridges on the soundboard, where the strings cross over, swells, making them to stretch, and therefore, raising the pitch.