Tuning A=440, 441 or 442?

What pitch to tune my harp to has been a particularly nerdy issue I have struggled with most of my orchestral life. I tune to A=442 as tuning to anything less than that makes the harp sound flat in an orchestra.

I use to worry about what long term effect on the harp tuning so sharp would have, so I would tune to A=441. Until I had a chat some years ago to Billy (the main Salvi/L&H technician in the UK) and he told me he regulates all the harps to A=442 as that is what they are built to be regulated at. He also regulates harps across Europe and South Africa. So any worry I had about the harps being regularly tuned sharper than they are built for was ungrounded as they are already built to be tuned higher then 440. German Horngachers, I believe, are built for A=444.

I wondered whether harps were being regulated to the same A=442 in the US and I found an interesting discussion on a US harp forum about it some years ago, so I'm glad it's not just me that has deep (quite sad) thoughts about the subject! Quite a few of US harpists on that thread seem to find issue with tuning so sharp.

I also found an even more interesting discussion on a US violin forum which gave lots of detailed insight into it from a string players point of view, and it makes a fascinating read.

So, when I was at Kneller Hall recently (which is the home of the Royal Military School of Music which trains musicians for the all of the bands in the British Army) I couldn't believe what I saw in their museum cabinet!!!

And there I was thinking tuning A=442 was potentially a tad sharp. Check out the pitch that the British Army bands used to be at! Information about it in picture below.

It makes tuning my harp at A=442 seem quite insignificant.

And yes, that is A=452!