Shruti is nothing but a minor variation of a note. Its esentially a frequency. Indian Classical Music has 12 notes and 22 Shrutis in all. In the ancient system of Shrutis, Sa had four variants, Re had three, Ga had two, Ma had four, Pa had four, Dha had three and Ni had 2. Thus Shadja, Madhyam and Pancham have four Shrutis each, Rishabh and Dhaivat has three each and Gandhar and Nishad have two each. In the ancient system of Shrutis a pure note was considered to be on its last Shruti. Hence the division was as follows
| 1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13 |
14 |
15 |
16 |
17 |
18 |
19 |
25 |
21 |
22 |
|
|
|
Sa |
|
|
Re |
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Ga |
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|
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Ma |
|
|
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Pa |
|
|
Dha |
|
Ni |
But as you can see because of this kind of placement of the notes, Ga and Re (also Dha and Ni) come very close to each other and hence Ga and Ni become komal. However this kind of a system is not in use today.
The modern style places the notes on its first Shruti instead of the las. Hence the division was as follows
| 1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13 |
14 |
15 |
16 |
17 |
18 |
19 |
25 |
21 |
22 |
| Sa |
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|
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Re |
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Ga |
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Ma |
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|
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Pa |
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|
|
Dha |
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|
Ni |
|
Thus the notes are pretty evenly distributed and can be easily sung.
