This is something I have always wondered about.
How is that musical notes across various cultures are of the same frequency ?
Separated by continents and time and evolving separately how did they end up using the same frequencies for the their notes ?
Citing an example.
Indian classical music has two main branches North Indian Classical or Hindustani and South Indian Classical called Carnatic.
They are broadly similar having identical scales and intervals but different vocal styles. Both are monophonic.
They both use the western classical intervals based on Concert A.
Oriental music though mainly pentatonic also use the same frequencies and can be played on a piano.
How did this happen ?
They are not. Various scales are constructed differently, end up with different numbers of notes, are tempered differently, and, last bot not least, are used differently (e.g., even the “same” scale can be used differently).
You mean that a lot of Indian & other Oriental music tends to use equal temperament as opposed to just intonation or whatever? It is not a topic I have studied extensively, but note that on one hand it is not always theoretically the case, e.g. construction of scales based on some sort of just intonation, or 22 shrutis or division of the octave into 53 or 72 equal intervals, or whatever. Practically, it will come down to tuning whatever instrument is used and also ease of singing. Also tradition, etc. I will leave it to Indian musicians to provide a satisfactory answer.
Well it makes sense that intervals like 8ths, 4ths, 5ths are not purely “Western”. As for concert A, if you mean A = 440 Hz, that has not always been a standard even in the West, but it is a sort of ISO standard now so at least a lot of software, MIDI, as well as actual musical instruments are tuned to it, so it is not too surprising that many people are using that standard.
The only reason I could see other cultures music being tuned to A440 (Western pitch standard, although some orchestras tune a tad higher – there’s been pitch inflation over the years, or whatever it’s called, as tuning slightly higher sounds a bit “brighter” to ears used to A440 – and there’s also been a bit of a fad to tune to A432 among new agey-types) is the influence of Western music. As said above, Western music itself has had a wide range of reference frequencies for A, going as low as somewhere in the mid 300s for certain German organs of the baroque era.
I am not an expert on this, however, this is just what I’ve synthesized over the years.
EDIT: A377 is the low concert A of the German organ I was thinking of (almost a Gb in A440), as mentioned here: https://www.wam.hr/sadrzaj/us/Cavanagh_440Hz.pdf
(And the highest as A567, or between a C# and a D in A440).
In Europe during the baroque era, the note called A went through a cycle of inflation. The choir director in one venue would decide that it sounded “brighter” to do Vivaldi’s or Bach’s latest with a slighly higher A (and other pitches going along with it of course) than the value typically used. The choir director in the village to the north would hear that and improve on it by notching it a few cycles higher yet.
I don’t recall how far it is considered to have shifted, but definitely upward, sharpward, before it became standardized at 440.
My question was not about scales but the frequency of the notes.
The Sa or C note in the scale of Sankarabharanam in South Indian Classical which is almost equivalent to C Major scale is the same. The C key on the piano.
This means a piano player who has not heard South Indian Classical music is can still play that note on a piano just by looking at sheet music.
What or who made the frequencies identical is my question ?
In that case, to make a long story short, it was ISO 16 (1955). But, as explained above, that did not come out of nowhere: a lot of instrument manufacturers and orchestras had been using 440 since the late 19th/early 20th century, and it seems to have been reached after a bout of pitch inflation. There is nothing magic about that number, and other standard concert pitches have been proposed (also not everybody is using it, even today).
From the link above, 435 Hz was a compromise, adopted in some countries, between sharp, more brilliant tuning like A = 450 Hz and lower tuning like A = 422 Hz, but there was still a bit of cheating since the room temperature was not specified, so the Royal Philharmonic got up to 439 Hz by 1896.
My guess is that cultures that have been introduced to western instruments and orchestras have aligned their pitch to the western A440.
The pitch intervals in the scale degrees are (were initially actually) based upon natural ratios that cylinders and especially strings provide.
When I looked up South Indian Classical compositions, most of them were composed in late 1700s to the mid 1800s by three composers called Thyagaraja, Deekshitar and Sastri. It would not be wrong to say their compositions make up the majority of South Indian classical music which is taught and performed in South India and the rest of the world to this day along with that of equally revered Swathi Thirunal who was born a few years after the Trinity.
How would they have based their compositions in such a way that it could be played on western instruments ? It seems the violin and the piano were introduced to India by the soldiers of the East India company. That would coincide with the lifetimes of the trinity. There is also mention of another musician called Baluswamy that actually adapted the violin in the 1700s to play Carnatic music with a different holding style ( the musician sits cross-legged on the floor with the violin resting on his leg) and tuning.
An 18th century musician called Venkatamukhi is credited with creating the Mela method of organizing notes into 72 full scales called Mela Kartha Ragas and the system by which one could derive more scales, pentatonic or asymmetric scales from them based on the time of day and the kind of feeling they evoke. Example Dawn, Dusk, Night, Love or Devotion.
So, since they could have had access to western music and instruments, do you think they would have set their music to the prevalent western music notes, essentially the pitch standard of the day ?
Pitch intervals are equally mysterious to me.
How early musicians arrived at the most pleasant to hear frequencies and made a 7 note scale.
I’ve had a few Egyptian musician friends who introduced me to the quarter note.
Took me a while to get used to it as it sounded to me at first like the instrument or singing was out of tune.
Then it took on a beauty of its own. Ancient hymns from Syria and Georgia make extensive use of the quarter note lending a very plaintive and lost quality to the music, that make people tear up.
The worst thing that could happen is that (say when playing an instrument designed for A=435 Hz instead of A=440 Hz) is that the scale would be transposed by a small interval. I don’t think that would irrevocably fuck up a composition?
Balaswami was Muthuswami’s brother: Carnatic Violin – Swararnava
Many of these scales (Greek, Arabic, Indian, etc.) are based on tetrachords instead of octaves:
In fact, that article explains exactly how to get the “72 Carnatic modes”
“Quarter tone” is the term you’re looking for there. It’s important as “quarter note” is a unit of note length, not relative pitch. While perhaps not part of the common practice period of Western classical music, microtonality does show up in the 20th Century and we even have a system of notation of half-sharps, half-flats, three-quarter-sharps, etc. And if you listen to pop/rock music, you will hear artists do stuff like sing in between a major and minor third (especially in blues – and you hear it a lot in guitar solos and riffs too, in the bends) to eke out that yearning, plaintive quality. So there will be intentional microtonal intervals, but used as an expressive “color,” not necessarily a foundational pitch in the scale
I think you have some fundamental misunderstanding about how scales and intervals have been standardized over the years. As pythagoras discovered, there are some mathematical reasons some notes sound good together, but (and I’m, likely badly, summarizing here as a lay person) if you try to apply all of those reasons over a full range from the lowest tones to the highest, … you just can’t.
That’s how different cultures have chosen different scales and the music still sounds “good”. (Although some people will find it “unfamiliar” and deem it bad on that basis.)
But these mathematical rules don’t care about the frequency you chose. So, as has already been pointed out, “concert A” isn’t some sort of cross cultural “correct” basis, it’s not even that old a standard in the west.
And that’s not the only thing that used to be a lot more up to individual composers, directors and musicians. The mathematical rules mentioned before don’t even play nicely across the range of our everyday music, and there were a lot of competing systems for fudging, so we don’t even know exactly how Bach was “supposed” to sound, because we don’t know the tuning he used.
Thank you. I guess quarter note was a local usage.
My misunderstanding apart which you have a habit of pointing to, I depend on the board to clear a lot of my misunderstanding, is it safe to assume that music as we know it would have sounded completely different until somebody adapted it / started playing it based on standard scales and pitch ?
Your statement on Bach was an eye opener 
That fully answers my question.
I would have liked to know who did that for Indian, Arabic and Chinese music. Possibly someone in the 1700s.
No. It would just have sounded a little bit different. At least to your average person. To musicians and composers it sounded sufficiently different for them to have opinions about the ideal choices.
That’d be nature. Well, certainly the basic octave and fifth.
Take a string (tuned to 440Hz or ANY frequency!), pluck it, enjoy that note… now hold it down it in the middle and pluck it, and you get the same pitch an octave higher. Press it a third of the way and you get the “fifth” (in the key of C, you’ve just played C, high C, and G).
Or if it helps, imagine a guitar where you’re playing a string open, then at the 12th fret, then at the seventh. Oh, you can also lightly touch the string and get the same notes as “overtones”.
Take a look at the diagram here. That’s why any octave anywhere works… it’s friggin’ physics, mate!
https://www.mtholyoke.edu/~mpeterso/classes/galileo/modes.jpg
That’s not exactly true, though. It depends on the instrument and its timbre. For instance, instruments like pianos and gamelans are tuned with stretched octaves. They are tuned so they sound “in tune”, taking into account overtones. E.g., https://sethares.engr.wisc.edu/mp3s/challoct.mp3
note that the octave is dissonant!
It’s already basically been covered: but yeah, not all cultures (or groups within a culture) arrive at thinking the same things sound good. The first thing I thought of when reading the OP was 24 Tone Equal Temperament, which they’ve already heard.
One of my faves to listen to is King Gizzard & the Lizard Wizard, who have released a couple of albums in this system. They totally rock.
And well, there was also Sonic Youth and other noise rockers who would tune several strings on their guitars almost but absolutely not in unison. It’s got a tonal center or root, but there’s no removing the dissonance from that, even if it’s a pop song about pop songs.
If the focus is on Arabic music, why not listen to some Arabic music? That way you can be sure the scale is used with the correct grammar.
I’m not certain this a reply to me, but my focus wouldn’t be on Arabic music. That was just the most convenient link to an article about that scale.
24-TET has been used elsewhere, and I like where it is used elsewhere more.
The movement for 432 wasn’t just about “new-agey types”. Many singers and players of antique string instruments began to be actually frightened when Sofia was up to A=454 and Berlin was rumored to be up to 460.