Yes that was a typo. I fixed itvasanthakokilam wrote:first a possible typo:
>2. S-R (both gramas), P-D (Y-grama)
Did you mean to write "2. S-R (both gramas), P-D (X-grama)"
Cannot say they are always wider. The first reduction is wider, the P-D interval of Y-grama than any swara spacing Sadja, Madyamagrama. But the X-grama is identical to Sadja grama. The Y-grama is same to Madyamagrama except for M-P-D part.vasanthakokilam wrote:Second, in this hypothetical 15 sruthi scheme, the sruthis are wider than the 22 sruthi scheme, right? I guess that is obvious but your initial setup itself demands that the resulting sruthis are less than 22 since you are picking a larger difference between Px-Py.
But yes the spacing will change # of sruthis - that was the point I was trying to make

Consider it another way. Sruthis are a sub-division of the spacing between swaras. Now again forget the sub-division. We still have spacing. In the combination of Sadja-Madyama grama there are 4 different spacings (ascending order):
1. Spacing I will label as S1. This is the spacing between the pas of the two grama (and is the only one that is a "inter-grama" spacing)
2. Spacing I will label as S2: R-G (both gramas), D-N (both gramas)
3. Spacing I will label as S3: S-R (both gramas), P-D (Sadja grama), M-P (madyama grama)
4. Spacing I will label as S4: G-M (both gramas), M-P (Sadja grama), P-D (madyama grama), N-S (both gramas)
Now Sadja grama has 2 S2s (R-G, D-N), 2 S3s (S-R, P-D) and 3 S4s (G-M,M-P,N-S)
Madyama grama as 2 S2s (R-G,D-N), 2 S3s (S-R,M-P), and 3 S4s (G-M,P-D,N-S). Basically same only difference being which pairs are S3 and which are S4
If these spacings are expressed in internal units i.e. sruthis, then we get 22.
How?
Simply make S1 = 1, S2 = 2, S3 = 3, S4 = 4.
So Sadja Grama = 2*2 + 2*3 + 3*4 = 22. Same for Madyama Grama.
It is extremely important to note that this assignment is NOT mathematical in the sense that the S-R interval (S3) is not precisely 3/2*S2 in terms of pitch distance. The 22 sruthis are NOT equal pitch distance. So the assignment can said "empirical" (? right choice?). Each decrement/reduction that was "discernible" *because* it was done such that the ending pitch of the swara which was prescribed as the starting point of the reduction - matched some pitch. IMO *that is how they defined* discernible (as opposed to minimally discerible change in pitch - which would have resulted in a larger number, but would also not be as easily accomplished as this one perhaps requiring technology?). That is how the ancients knew how much to reduce. But each such reduction was taken as an atomic unit (sruthi). But consecutive reductions need not be same - they were of amounts of "whatever was needed to get to that discernible point i.e. a destination pitch matching some swara" and that whole reduction amount was taken as an atomic unit.
Note the S1 spacing does not occur WITHIN a grama - but it plays an importtant role. Without it (say no madyama grama) perhaps you would have just 3 spacings. Perhaps got labelled 1, 2 and 3 and you would end up with 2*1 + 2*2 + 3*3 = 15
(interesting usnt' it? I got 15 for X-Y, using a different but similar approach in the sense I eliminated S1 from the picture in a different way)
The assumption/presumption is you knew it by ear based on the melodic nature of the scales, and . we knew the "approx" spacing of swaras "by ear" - we just dont know if there are any sub-units in between and how many.But I have a significant question on this.
>1. R-G (both gramas), D-N (both gramas), P-M (Y-grama), Px-Py (difference between the two gramas)
I can see how one can satisfy your stipulation that P-M ( Y grama ) is same as R-G. That can potentially be done by ear. But how did Px-Py become equal to R-G. That is critical to your first inference. May be I am missing something.
Consider this: Does one have to show by experiment in order for the ancients to know the G-M spacing < S-R spacing < N-S spacing? I think not. I think they had an reasonable idea of what the spacingswere and their order.
So that was why I laid those down. If I didnt lay those down, and I said when I dropped Pa of X2 to Pa of Y, the Ga of X2 also matched Ri of X2 - one could ask "uh? Come again?"

(PS: no matter how "fair" those pictures looked, it is either not possible or extremely hard to represent the spacings through the experiment with ASCII text - atleast I had to struggle a lot)
Again it is not a stipulation per-say. In my hypothetical X-Y grama pair that was the "observation" which again I presumed can be "judged" by ear (i.e. based on the melodic nature of these hypothetical scales). One needs to that to tune the vina by ear.( Also, your stipulation that "pa of Y is mid-way between the ma-pa of sadja grama, is it just a mention in passing since you also prescribe that it is located at the same distance from M as R-G or is that significant as well?).
For example, how do we know that S-R2 is about the same distance as P-D2? Only because pitch analysis says both are about 200 cents? Or does our ear+brain already think they are close enough and pitch analysis simply validates that.
No. They are never "equally spaced sruthis" even in the 22 sruthis (viDiya viDiya rAmAyaNam ...BTW, are we taking it in good faith that all these reductions amount to 'equally spaced' sruthis?

The only "consistency" is the reduction at each step is the same for the entire vina.
Arun