In Indian classical music, Shruti (derived from the Sanskrit root shru—”to hear”) refers to the smallest, most subtle microtonal interval or graduation of pitch that the human ear can perceive and a musician can produce. While there are 12 semitones in an octave (swaras), Indian music traditionally recognizes 22 shrutis, which serve as the foundation for the seven main notes, providing the nuanced pitch variations that give each raga its unique emotional identity.
Shruti is a term with many meanings, ranging from the simple to the complex. One of the technically sound definitions of Shruti is that it refers to musical positions which are a certain distance away from the starting frequency, which is called Tonic. Many claim that there are 22 such positions in an octave.
A full scale of 22 shrutis
In addition, komal notes can have two flavours (for Re Ga Dha Ni):
- Ati Komal: very flat
- Komal: flat
In addition, shuddh notes can have two flavours (for Re Ga Ma Dha Ni):
- Shuddha: natural
- Teevra Shuddh: sharper than natural (Teevra Shuddh X means Higher version of Shuddh X, it doesn’t means Teevra).
In addition, teevra notes can have two flavours (for Ma):
- Teevra: sharp
- Teevratama: very sharp
As you can see, each of these 5 notes has 4 shrutis possible.
At last, this is forming a full scale of 22 shrutis (2 + 5 * 4 = 22), with precise fractions, mathematically accurate and musically pleasant and divine. These 22 Shrutis are not theoretical postulates, but solid musical facts that provide the foundation of Indian music, and have been used for centuries. Many of these notes are known and used since more than 2000 years is several cultures, from Babyloniens, to Greeks, and closer to us, some musical systems used in europe before the generalisation of 12 equal tones temperament.
From these 22 shrutis, rāgas will be built, by extracting notes. For each rāga, the selected shrutis will become the swaras of the rāga. We will say shrutis for the possible notes present in the music system, and swaras for the selected notes of a rāga.
For Hindustani Classical music or Carnatic Music, 22 shrutis are nearly the same. Although, they do not have the same names, and they are not all used in both systems.
Each shruti is assigned a sargam, which identifies its place in the list of 22 shrutis. The same sargams are used for Hindustani and Carnatic classical music, but the shrutis have a distinct full name in each of the musical systems.
These shrutis are mathematically correct, with well defined ratios, scientifically perfect and the musical result is divine.
Shruti vs Swara: Understanding the Difference
This is a common point of confusion for learners and parents.
| Term | Meaning |
| Shruthi | The reference pitch or micro pitch space |
| Swara | The musical note we actually sing (Sa, Re, Ga, etc.) |
| Shruthi (Drone) | The continuous sound used to maintain pitch accuracy |
Simply:
- Shruthi is the reference
- Swara is the note
- The drone helps you stay aligned
Sargam of shrutis for north indian classical music
The shrutis will be named as follow for Hindustani Classical Music (some of them are unused in Hindustani music):
- S: Shadja
- r1: Ati komal Re
- r2: Komal Re
- R1: Shuddha Re
- R2: Teevra Shuddh Re
- g1: Ati komal Ga
- g2: Komal Ga
- G1: Shuddha Ga
- G2: Teevra Shuddh Ga
- M1: Shuddha Ma
- M2: Ek Shruti Ma
- m1: Teevra Ma
- m2: Teevratama Ma
- P: Pancham
- d1: Ati komal Dha
- d2: Komal Dha
- D1: Shuddha Dha
- D2: Teevra Shuddh Dha
- n1: Ati komal Ni
- n2: Komal Ni
- N1: Shuddha Ni
- N2: Teevra Shuddh Ni
Sargam of shrutis for Carnatic music
This shrutis will be named as follow for Carnatic Music:
- Sa
- r1: Ek shruti Re
- r2: Dvi shruti Re
- R1: Tri shruti Re
- R2: Chatu shruti Re
- g1: Shuddha Ga
- g2: Sadhanran Ga
- G1: Antara Ga
- G2: Chyut madhyam Ga
- M1: Shuddha Ma
- M2: Teevra Shuddha Ma
- m1: Prati Ma
- m2: Chyut Pancham Ma
- Pa
- d1: Ek shruti Dha
- d2: Dvi shruti Dha
- D1: Tri shruti Dha
- D2: Chatu shruti Dha
- n1: Shuddha Ni
- n2: Kaishiki Ni
- N1: Kakali Ni
- N2: Chyut Shadja Ni
Three shrutis differ from both scales:
- r1: Ati komal rishabh is very very komal in Carnatic music, quite close to Shadja
- m2: Slightly different between both systems, but very close
- N2: Chyut Shadja Nishad is very very teevra in Carnatic music, quite close to upper Shadja
Why is Shruti Important in Music?
- It helps musicians stay perfectly in tune, reducing pitch errors.
- It gives children a fixed musical “home base” to develop a strong sense of pitch early on.
- It supports accurate practice by helping students check whether their notes match the reference sound.
- It builds confidence—when Shruthi is correct, everything instantly sounds more musical.
- It trains the ear to identify pitch relationships, which is essential for singing and playing any instrument.
Why Shruti Doesn’t Exist in Piano and Harmonium
- Fixed Tuning System: Both the piano and the harmonium use 12 equally spaced intervals to divide an octave. Indian music, however, relies on 22 shrutis—mathematically precise microtonal intervals based on natural ratios rather than equal division.
- Abolition of Microtones: In the 12-TET system, the notes are “tempered” to sit in between the higher and lower shrutis. This “compromise” tuning completely eliminates the subtle microtones needed to express the true bhava (emotion) of a raga.
- Inability to Slide: Shruti is often expressed through meend (gliding between notes) and gamakas (ornamentations). Because pianos and harmoniums have fixed, separate keys, they cannot produce these continuous slides, making it impossible to reach the microtonal pitches located “between” the keys.
The Instrument That “Avoids” Shruti: The Harmonium
The Harmonium is the primary instrument that effectively “avoids” or overlooks traditional shruti values.
- Historical Conflict: Because it follows Western tuning, the harmonium was actually banned by All India Radio for 30 years (1940–1971). Purists argued it diluted the purity of Indian notes and was “unsuitable” for authentic classical accompaniment.
- Convenience over Purity: Despite its technical limitations, the harmonium remains popular because it is loud, easy to learn, and provides a stable melodic reference for group singing and beginners.
- A Modern Solution: To fix this, some inventors have created a 22-Shruti Harmonium, which adds extra reeds or knobs to allow players to access the microtonal intervals missing from the standard version.
Instruments That Preserve Shruti
Unlike the piano, instruments like the Sarangi, Violin, and Veena are designed specifically to capture shrutis. Since they have no fixed frets (or curved frets in the case of the Veena), the musician can glide their fingers to find any of the 22 precise pitch positions.
Shruti veena: The sound link
After achieving Bharat’s scale on sitar Dr. Misra modified traditional Rudra Veena. In order to turn it in to Shruti Veena following changes were made —
1. Instead of bamboo (Vansh), wood was used for the finger – board or stem without changing Veena’s basic structure.
2. Tar Gahan and Bridge were made in such a way so that they can bear five strings over frets with equal distance.
3. Tar Gahan and Bridge were made of same height, with flat top and with no curve.
4. Straight frets were fixed in such a way that minimum pressure should be used while pressing the wire.
5. Two steel strips were placed both sides of the stem. Same arrangement was made on frets so that they can be hooked through these strips and can also be re adjusted if need be.
6. Discarding Chikari wires five strings from same coil were used. With above changes Rudra Veena is transformed into Shruti Veena.
After Shruti Veena’s physical change next step is to tune Shruti Veena in to Shadaj Gram. For this the first step will be to tune all the five strings of Shruti Veena in accordance with the already tuned sitar’s free strings. Second step will be to adjust all the frets of Shruti Veena according to the pre- tuned Sitar’s Frets. In this manner whole Shadaj Gram is transferred to Shruti Veena.
By pressing all five strings simultaneously on each note of Shadaj Gram we can check the accuracy of the Shadaj Gram on Veena. If there is any difference of sound we must tune it perfectly.
Method of Chatus-Sarana on Shruti Veena
1. Presume first wire from left as ‘Achal Veena’ and press ‘Rishabh’ on the same string. Again press and strike ‘Pancham on second wire. It can be observed that these two notes do not correspond with each other. Second wire should be loosened so that ‘Pancham of second wire is lowered until it is in consonance with Rishabh of first wire. When these two notes are in complete harmony with each other consider that first Sarana is complete and first Shruti has been achieved. One can check that in second wire all the notes are one Shruti lower in compare to first wire which is the original Shadaj Gram.
2. For second Sarana again press Rishabh note on first wire and Gandhar note on third wire. Now, lower the third wire as much so that the sound of Rishabh on first wire can be brought on the place of Gandhar on third wire. When the sound of Rishabh on first wire and sound of Gandhar on third wire unites consider second Sarana is complete. Now, third wire is two Shruti-s lower than first wire. With the same process the sound of Nishad of the third wire will merge into the sound of Dhaivat on first wire. In this Sarana all the remaining notes will be lowered by two Shruti-s.This was Bharat’s second Sarana.
3. In third Sarana again free wire is played to produce the sound of Shadaj on first wire and Rishabh fret is played on fourth wire as well. With lowering the fourth string up till the sound of Rishabh on fourth wire merges into the Shadaj of the first wire third Sarana is complete. With the same procedure Dhaivat of fourth wire will also merge into the Pancham of first wire.
4. In fourth Sarana, Madhyam on first wire is played and Pancham on fifth wire is played. Now, lower the fifth wire until Pancham of fifth wire merges into the sound of Madhyam on first string. With this process Madhyam and Shadaj of fifth wire will also merge in to Gandhar and Nishad of the first wire.
After achieving all the 22 Shruti-s with all the five free strings we can see the difference of four Shruti-s. Difference between first and second wire is the smallest difference which is of 5 savart. Interval of second and third wire is largest with 23 savart. Difference between third and fourth wire is again of 18 savart. Again, between fourth and fifth wire there is a difference of 5 savart.
In understanding the above process, animation on Swar Gram and Chatus Sarana might help. Shruti Veena is the only instrument on which all twenty two shruti-s may be heard simultaneously. It establishes the mathematical basis of Indian Classical Music.
The original instrument is still in collection of music department at BHU. I have learnt that despite ravages of time it is still intact. Repeated pleas to instrument makers for replicating it have been in vain as yet. I am sure that in future some enthusiastic craftsman would help me build another Shruti Veena. To date, this is the only means available to understand both Bharat’s Chatuh Sarana process as well as hear the Shruti-s.
How to Practise Shruthi
For Singers
- Begin every practice session by singing Sa, Pa, and higher Sa along with a Shruthi drone.
- Hold each note for a few seconds and check if it blends smoothly with the Shruthi.
- Practise simple patterns such as Sa–Re–Sa and Sa–Ga–Sa to build pitch stability.
- Avoid rushing—sing slowly to allow your ear to adjust to the reference pitch.
- Record short singing clips to check if your Shruthi alignment is consistent.
For Instrument Players (Piano, Guitar, Keyboard, Ukulele)
- Match the instrument’s tuning to the Shruthi you select before playing.
- Play long, steady notes along with the drone to develop pitch awareness.
- Practise basic scales or chords while listening for a blend with the Shruthi sound.
- Keyboard players can play the Shruthi note alongside exercises to reinforce pitch sense.
- Guitar/ukulele players can tune strings using the Shruthi as a reference.
For Beginners at Home
- Use a mobile tanpura app set at a comfortable Shruthi for your child.
- Start with simple listening exercises—ask your child to hum softly along with the drone.
- Spend 5 minutes daily matching a single note (Sa) to the Shruthi.
- Create a fun game: “Does it match?” where your child checks if their voice blends with the Shruthi.
- Keep sessions short, light, and encouraging so the child feels confident.
Common Mistakes with Shruthi (and How to Avoid Them)
- Singing without a reference Shruthi → Always start practice with a tanpura, a pitch App or shruti box.
- Choosing a Shruthi that is too high or too low → Select a pitch that is comfortable, not challenging.
- Rushing through notes → Slow practice helps your ear lock onto the Shruthi.
- Not checking pitch frequently → Pause often to compare your note with the Shruthi.
- Depending only on memory → Use a drone every day to strengthen ear training.
