I'm working on a Henry & S.G. Lindeman vertical piano made between 1901 (when that brand name began being used, I read) and maybe 1930. Relatively simple exterior, but with like Roman columns, so I'm thinking it's maybe 1915 to 1925. I forgot to write the serial number. It's very stable in tune with itself but 50 cents flat. It was clearly tuned at that pitch. A is at 427.
My question is, if I do a pitch raise to 440, am I likely to have any problems?
I have done only one or two pitch raises, and the main one I did was on a much newer Kawai. I'm playing a gig on this Lindeman piano Mothers Day and will have access to it in a quiet environment all day long one day about a week before then. So what I'm trying to decide is whether I should do a pitch raise or leave it at 427. I practiced on it at 427 and it sounds good but had me in a melancholy mood, and I really want the gig to go well. I read that 440 was only standardized in 1940. What pitch were pianos usually tuned to before then?
The angle of the bass strings over the termination is pretty near straight, so I think they're not too likely to break.

Charles,

There is a 95% chance that you will have no problems at all. However, I would be inclined to not overpull by more than 6-10 cents, which means you will need to go over it more times. No need to worry about the pitch level back then. The structure and strings can easily take it at 440 and beyond (they were overbuilt). The only issue now is an assessment of the current structure, and state of the wire. From what you said it sound's like the wire has been under-stressed for a long time, therefore it should have plenty of strength. If severely rusted though, that could be a different story.

If a string breaks, splice it. If two break, slow down. If three break, re-assess the situation. This is your 5%. The odds are in your favor.

Pwg

Measure the speaking length of note 88. If it is over 55mm, the risk of breakage is high. If it is at the more standard 49-52mm length, not much risk if it is not rusty.

I agree with Peter here. The only thing I would add is that I would recommend CLP lubricant to help the strings move to avoid breakage. You can buy from Piano World.

Another thought: Instead of going for A440 maybe go for A435 which would be more historically correct. Around the era of the piano A435 was "standard" pitch and A440 was "concert" pitch. Unless you'll be playing with other instruments there's no compelling reason to get it up to A440.

Wow that's exactly that info I was looking for. Thank you!

I have CLP and didn't know to use it for this purpose.

Good advice on lubriction.

However, (not to be intentionally contradictory [Scott] 😊) if the thing survives at 435, it will also survive at 440. The ACTUAL difference in overall tension throughout the scale is less than 1000 lbs. And, since in order to get it to 435 you will need to exceed that temporarily, if nothing breaks in the process, you have circumstantial evidence that 440 would also be attainable.

When the "standard" pitch changed, the piano companies did not go back and "redesign" everything with 440 in mind. They simply yanked them up to 440 because they knew the structure could take it.

In the final analysis it us your choice, but in 43 years I can probably count on one hand the number of pianos that I have specifically NOT brought up to 440, and only for the specific reasons I mentioned earlier.

Have fun. Let us know how it turns out.

Pwg

Check the bridges, especially the bass for any signs of splitting or string movement side to side. If they are fine, the piano will likely be able to take the extra stress

Follow-up: The pitch raise went smoothly and without any strings breaking. I had inspected the bridges on a previous visit and everything looked good. I had planned to measure note 88 but I was short on time and just looked at it and to my eyes it didn't seem unusually long. I also took a risk and didn't lubricate the strings. (sometimes I like to learn the hard way if a penalty isn't too great, like if a string had broken). I only overpulled by about ten cents, maybe up to 15 on some strings on my quick first pass. (I noticed that the upper third of the keyboard needed more passes than elsewhere; I did about three there; enough for the stretch to sound big and bright but I think it's still a couple cents flat; It's not a perfect tuning but it's absolutely at my own musical standards; I'm the one playing and I did the tuning for free).

Something related to this topic that I find interesting is that when tuning my 1907 reed organ today I found that it seems to be at 440. If not it would have to be very close like 438, but it's definitely not 435. I had expected 435. I'm guessing they thought that with it being so time consuming to tune an organ they would go with "concert" rather than "standard" and be on the safe side in some sense.

Reeds vibrate faster as they get fatigued, so your reed organ may have been at 435 originally. However, they vibrate slower if there is a lot of dirt on them, so it may have been at 440.

I've cleaned them and they're close to being in tune with each other (musical enough that I was able to take it out busking for four hours yesterday), so I don't think fatigue raised their pitches, because it would have to be so uniform on all 233 reeds). Another clue that it was 440: the celeste rank is actually (uniformly) above 440 (as it should be because celeste is tuned sharp.)

Charles,

Glad everything went well.

In the last few years I have opted to reduce my overpulling in pitch raises quite a bit. Of course this means I must go over it more times, but I personally feel it is better for the piano, and less likely to inadvertently pull a string (or strings) to the point of deformation.

Also, when I restring a piano, I no longer overpull the new strings (hardly), nor do I excessively massage them to "accelerate stretch" (there is controversy over whether "stretching" actually occurs or if it is simply the bends straightening...doesn't matter to me anyway). I just let them do their thing in their own time frame. Circumstantial evidence to this point seems to validate the efficacy of this approach.

As to your reed organ, 110 years of history leaves open a number of possibilities that may be difficult to nail down the facts.

Just my .02

Pwg