I have had my wire-strung Kilcoy harp for about a decade, and in all that time, I've never had a string break. I had one go just before the winter solstice, and I had another go last month.
Well, I said to myself, maybe ten years is just the lifetime of these bronze strings. They'll all be going soon.
I took out my poor neglected instruments two nights ago to tune them up. Both were about two tones flat! I started tuning, but it seemed really hard to raise past a tone - so, not wanting to snap strings, I left them tuned a tone flat. The next night, I raised another semitone so that I was only a semitone flat. Almost there.
The third night, last night, I sat down to bring them all up to tune. I took up my electronic tuner - and stopped. The temperament indicator wasn't 'PG,' the Pythagorean I usually use. As I cycled through my options to set that correctly, I noticed that the calibration indicator was no longer set to A = 440 Hz. It was some random number like 483 Hz. A memory came back to me in a flash - taking the tuner away from one of my boys, telling him to stop pushing buttons.
I cycled the calibration back to 440 Hz and picked up a harp. Sure enough, I was a half-tone sharp. I relaxed all of the strings and, except for the new string that's still settling in, everything was in tune.
If I've been tuning almost an entire tone above where the harp is supposed to be tuned to (B = 494 Hz), no wonder I lost two strings!