Shruti (music)
The śruti (Sanskrit "thing heard", "sound"; written also sruti or shruti) is the smallest interval of the tuning system in Indian classical music (which are not the same as that of 12 note Western scales).
Sruti types
Canonically, there are 22 śruti in the octave, although systems with more or fewer śruti have been proposed. Here they are given in terms of just intonation, although many authors assume schismatic temperament implicitly.
There are infinite ratios, and therefore kinds of śrutis, in Indian Music as there is full freedom; Yet classical described are
- Chatuh sruti : 9/8
- Tri Sruti : 10/9
- Dwi sruti : 16/15
- Single or Mono sruti : 81/80 which is called pramana Sruti.
Further there are Antar-sruti which give distances within one sruti and show how distances were formed:
- 2:1 is taken as distance between same Swar sruti Sa to Sa, Re to Re Ga to Ga & likewise. this was placed on "4 th sruti"
- 3:2 is distance between Sa & Pa that is ist tone & 5th tone. this was placed on "17th sruti"
- 4:3 is taken as distance between Sa & Ma Shuddha this was placed on "13 th sruti"
- 5:4 is taken as distance between Sa & Ga Shuddha this was placed on "9 th sruti"
- 6:5 is taken as distance between Sa & Ga Komal which was called teevra in old ages as moving Ga towards Re makes Re Suddha
Shrutis & their frequencies
Sadja below is assumed to be A#.
| Shruti Name | Ratio | Shruti Frequency(Hz) | Note Name | Note Frequency(Hz) | Swara |
|---|---|---|---|---|---|
| Kshobhini | 1 | 466.1638 | A# | 466.1638 | Shadja |
| Tivra | 256/243 | 491.1026 | B | 493.8833 | Komal Rishabh |
| Kumdavati | 16/15 | 497.2414 | |||
| Manda | 10/9 | 517.9598 | |||
| Chandovati | 9/8 | 524.4343 | C | 523.2512 | Shuddha Rishabh |
| Dayavanti | 64/54 | 552.4904 | C# | 554.3653 | Komal Gandhar |
| Ranjani | 6/5 | 559.3966 | |||
| Raktika | 5/4 | 582.7048 | |||
| Rudri | 81/64 | 589.9886 | D | 587.3296 | Shuddha Gandhar |
| Krodhi | 4/3 | 621.5517 | D# | 622.2540 | Shuddha Madhyam |
| Vajrika | 27/20 | 629.3211 | |||
| Prasarini | 45/32 | 655.5428 | E | 659.2552 | Tivra Madhyam |
| Priti | 729/512 | 663.7371 | |||
| Marjani | 3/2 | 699.2457 | F | 698.4565 | Pancham |
| Kshiti | 128/81 | 736.6539 | F# | 739.9889 | Komal Dhaivat |
| Rakta | 8/5 | 745.8621 | |||
| Sandipini | 5/3 | 776.9397 | |||
| Alapini | 27/16 | 786.6514 | G | 783.9909 | Shudddha Dhaivat |
| Madni | 16/9 | 828.7356 | G# | 830.6095 | Komal Nishad |
| Rohini | 9/5 | 839.0948 | |||
| Ramya | 15/8 | 874.0571 | |||
| Ugra | 243/128 | 884.9828 | A | 880.0001 | Shuddha Nishad |
| Kshobhini | 2 | 932.3276 | A# | 932.3276 | Shadja |
See also
References
- Lentz, Donald A. Tones and Intervals of Hindu Classical Music. University of Nebraska-Lincoln, 1961.
- Deva, B Chaitanya The Music of India: A Scientific Study.
- Rao, Suvarnalata Acoustical Perspective on Raga Rasa Theory.
External links
- www.soundofindia.com Article on Śrutis by Jeyanthe Ratnakumar
- [1] A website showcasing the revolutionary research on the 22 sruti's in India music, and pin-pointing their positions mathematically.
- 22 Sruthi Keyboard Tuner Application "22 Sruthi Keyboard and Just Intonation tuner for Sitar and Veena" , Version 2.2 for Windows XP.
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