Logic behind 22 Shrutis

 Shruthi is a Sanskrit work,  Shruthi is  sound capable of hearing from the ear.,

1). Sound capable of being used in Music.

2). Sound which can be distinctly heard by the ear.

3). Sound which can be identified one from the other.

Pleasing sounds to the ear called "Swears"   and every sound which is not musical hurts the ear is called,"Apswara" or "notice"

The Logic behind 22 Shrutis (‘Shruti-Nirman Chakra’)

The ancient logic on how different musical notes are created in a Spartak is very insightful and relevant.

The fundamental notes in music are S and P and the Tanpura is tuned to these notes for the same reason.

Other than P, the next important note is M because, the upper S' becomes the P of it.

The natural ratio of the frequencies of S:P is 100:150, and of S:M is 100:133.33333. These are obtainable after an analysis of an extremely well-tuned Tanpura. In other words, from any musical note (taken as 100), the note at 133.33333 % is it's Madhyam, and the note at 150 % is it's Pancham.

Therefore, beginning from any Shadja, if we continue the S:P cycle ahead by adding 50 % to the frequency of the earlier note, we shall complete the cycle, coming back to S' and giving 12 positions or places.

Similarly, if we continue the S:M cycle ahead by adding 33.33333 % to the earlier note, we shall complete the cycle, coming back to S' giving 12 additional positions or places.

In total, 24 places or 24 musical notes are obtained. (Refer to following figure)

Figure shows 'Shruti Nirman Chakra'The clockwise cycle is Shadja:Pancham (S:P) and the anticlockwise cycle is Shadja:Madhyam (S:M).

Thus, we get 24 places or musical notes or shrutis at the natural ratios of S:P and S:M.

Out of these, S and P have been considered 'Achala' or immovable or fixed by our ancestors. Subtracting these 2 from 24, we get 22 Shrutis.