Only 38 Swiss Francs (~40USD, ~35EUR) to review this standard! So if I want to make an ISO standard instrument do I need to buy all the other notes too?
Eww, only 0.5 Hz tuning accuracy on that 440 Hz? That’s two cents (2⁄100 of a semitone). As an amateur with a not-terribly-high-quality piano I’d be ashamed to tune it two cents off; you really want to get within one (and you need the difference between same-pitched strings to be a good deal finer than that). I’d expect less than half a cent from a professional tuner on a decent-quality piano.
Unless the spec goes into more restrictive detail, you could tune a piano’s A440 honky tonky (roughly: one string 439.5 Hz, one string 440.5 Hz) and still be ISO-16:1975–compliant.
Funny. I was reading about the Schiller institute just today. They are a crazy bunch, and for some reason they chose (among a great deal of actually legitimate figths they have) to have an opinion on that.
As an orchestra musician, I don't believe an orchestra can ever go down below 440. Trying to play any modern wind instrument at those pitches would sound awful and just pitching them down would not work. If I would go to Heckel (the bassoon brand I play, because they have been the best (and most expensive by far) for about 200 years) and ask them to make a 432hz-pitched bassoon they would laugh at me.
I think there has been a drive slightly downwards since the 60s, mainly because instruments and players have become better. Sure, the Vienna Philharmonic might have started at A=440hz, but ten minutes into the recording it has already at 444. I have tried to do play-along to those recording (when fast-learning an orchestra part), and by the end of the movements I can't get up that far.
In my orchestra (80 musicians, triple winds. In Sweden) we start 442, and usually end slightly above 443 (sometimes higher, depending on heat and repertoire). I recently played a concert in the Swedish radio orchestra, and they are amazingly consistent.
Putting aside that notes don't really have to be in tune to be notes, this is not where A=440hz originated.
Correction: upon further research, this is where 440hz originated. However, it was not the original standard (or where musical notes come from), and I find the history interesting, so I'm going to post it anyway.
Tuning used to be based off of whatever instrument was not easily tunable (the piano or organ), or some other instrument (oboe?) if there was none. For much of musical history tuning was significantly lower than A=440, albeit with a lot more variation; however, it tended to rise[0][1] in order to create a more brilliant-sounding timbre (particularly in larger venues), especially among instrumental pieces. This led to some contention, especially with vocalists who found the increasingly-high notes more and more difficult to sing. There were several efforts to readjust tuning to something more reasonable, but ultimately none of them worked for long.
Frequency was actually orignically standardized in Article 282, section 22 of the Treaty of Versailles.[2] This may not make a lot of sense at initial glance, but when thinking about it as how good orchestras sound, it does make some sense as an economic policy
This is where I originally messed up, though. The Treaty of Versailles references something else (which I don't have a link for), but which, per [1], standardizes to... 435hz. But again this crept up, and apparently the US and UK did some shenanigans with interpreting it (the UK changed the temperature to get it to 439hz, I haven't found out precisely what the US did), and there was again some debate. Some people gave up and standardized with the UK to 440hz, some stayed at 435, and eventually the ISO did step in and standardized again on 440.
So we may all be breaking international law by tuning to 440hz.
Though they spoil the plot in the abstract.
https://www.iso.org/standard/3601.html