Mridangam tuner: right head on your shruti
A mridangam is tuned to a single note. The right head, the valanthalai with the black karanai in its centre, goes to the shruti (Sa) of the singer or soloist; the left head, the thoppi, has no fixed target. The shruti is named by its Western note or by its kattai number: 1 kattai is C, 1½ C♯, 2 D, 2½ D♯, 3 E, 4 F, 4½ F♯, 5 G, 5½ G♯, 6 A, 6½ A♯ and 7 B. The B below C is ¾ kattai, sometimes written 0.
Kattai, Sa and chapu target
Each kattai with its Sa and the note where the chapu sounds strongest (second harmonic). Equal temperament, A4 = 440 Hz. Drum sizes follow one teacher's guide, not a rule.
| Kattai | Sa | Chapu target | Frequency (Hz): Sa / chapu | Usual drum |
|---|---|---|---|---|
| ¾ (or 0) | B2 | B3 | 123.47 / 246.94 | Thagu, 24–26 in · male singers |
| 1 | C3 | C4 | 130.81 / 261.63 | Thagu, 24–26 in · male singers |
| 1½ | C♯3 | C♯4 | 138.59 / 277.18 | Thagu, 24–26 in · male singers |
| 2 | D3 | D4 | 146.83 / 293.66 | Thagu, 24–26 in · with instruments |
| 2½ | D♯3 | D♯4 | 155.56 / 311.13 | Thagu, 24–26 in · with instruments |
| 3 | E3 | E4 | 164.81 / 329.63 | Thagu, 24–26 in · with instruments |
| 4 | F3 | F4 | 174.61 / 349.23 | Sthaayi, about 22 in · female singers |
| 4½ | F♯3 | F♯4 | 185.00 / 369.99 | Sthaayi, about 22 in · female singers |
| 5 | G3 | G4 | 196.00 / 392.00 | Sthaayi, about 22 in · female singers |
| 5½ | G♯3 | G♯4 | 207.65 / 415.30 | Sthaayi, about 22 in · female singers |
| 6 | A3 | A4 | 220.00 / 440.00 | Sthaayi, about 22 in · female singers |
| 6½ | A♯3 | A♯4 | 233.08 / 466.16 | Sthaayi, about 22 in · female singers |
mridangams.com (Sriram Venkataraman) — Size, shape, measurement, pitch of Mridangam
How to use it
- Choose the profile with your shruti, for example 5 kattai · G, or the free profile for any other note. Press Hear target to hear the Sa.
- Tap Turn on microphone, keep the phone about a forearm's length from the drum and play a clean chapu near the edge of the valanthalai. Let it ring: the sustained sound counts, not the first instant of the stroke.
- Correct with the stone and the pullu, the small wooden peg resting on the straps at the edge: a tap from above raises the pitch, a tap from below lowers it. On a nut-and-bolt mridangam, turn the bolts with the key a little at a time; tightening raises the pitch.
- Play the chapu at several points around the rim and adjust until every point reads the same note. Finish by ear against a shruti box, tanpura or pitch pipe on the same Sa.
Help and explanations
Each profile here is one kattai. Its main target is where the chapu (cha) sounds strongest: the second harmonic, the Sa one octave above the drum's fundamental. On a 1 kattai mridangam the chapu reads around C4 (261.63 Hz); on 5 kattai, around G4 (392.00 Hz). A second button holds the same Sa one octave lower, because many phones read the chapu there. Either button in green means the valanthalai is on Sa.
Why the reading can show another octave
The chapu, the open stroke on the edge of the valanthalai, is the stroke used to tune the mridangam to the main artiste. The review of Musical Excellence of Mridangam (U. K. Sivaraman, T. Ramasami and M. D. Naresh) reports that it mainly excites the second harmonic: you hear Sa, while the strongest partial sits an octave above the fundamental. In recordings of a professional mridangist with drums tuned from B to E, that partial fell between B3 and E4.
A tuner can lock on to the fundamental, the second harmonic or even a higher one, so the same chapu may show C3, C4 or C5 on a drum in C. That is why each profile has two buttons. Look at the note name first: if it is right but the octave matches neither button, the drum is fine; set Transpose to +12 or −12 under Settings. Also wait a moment after striking, because the first tenth of a second carries partials that do not follow the Sa.
Chapu, not dheem: choosing the stroke
Do not tune with the dheem. Its lowest mode is shifted, roughly one to two semitones above Sa, and the stroke mixes in low resonances, so the reading comes out wrong or unstable. The nam (meetu) and the araichappu are not good reference strokes either: their strongest partials change and the needle jumps. Strike the chapu at the same spot and with the same force each time.
The pitch must be even all the way round. If the needle settles at one point and not at another, that part of the head is higher or lower: correct only there, then play the whole circle again.
Which kattai suits which drum
One teacher's guide (Sriram Venkataraman, mridangams.com) gives two families. The thagu shruti mridangam, about 24 to 26 inches long, serves male singers from B to C♯ (¾ to 1½ kattai) and goes up to E (3 kattai) with violin, veena or flute. The sthaayi shruti mridangam, about 22 inches, serves female singers from F to A♯ (4 to 6½ kattai). A scientific review of the instrument also notes that the length depends on the shruti needed.
Treat these ranges as a guide, not a promise: every shell, head and set of straps has its own comfortable range, so do not force a drum far from where it rings well. Shruti boxes and flutes use the same kattai numbers, so a 5 kattai concert has Sa = G for everyone on stage, tanpura included. Without a shruti box, play the online tanpura on your Sa.
Thoppi, reference pitch and what the tuner does not do
The thoppi gets no target. Some players leave it equal to the chapu or an octave below, but the rava paste applied before a concert lowers it and its sound does not follow the Sa, so this tuner leaves it free. The same straps hold both heads, so check the valanthalai again after working on the thoppi.
Frequencies here use equal temperament with A4 = 440 Hz, like electronic shruti boxes; the tradition has no fixed A. If your shruti box or harmonium sits slightly away from 440, use Capture reference or change Reference A under Settings. The tuner checks the pitch of the valanthalai; tone, the balance of strokes and the final check by ear, the sruthi jnana, stay with you and your teacher.
Tips
- Give the pullu light taps with the stone and play the chapu after every few taps: small corrections are easier to control than one hard blow.
- Switch the shruti box or tanpura off while reading the chapu, so the microphone hears only the drum; switch it back on to confirm by ear.
- Tune in a quiet room, with the phone at the same distance each time.
Frequently asked questions
What note is 5 kattai shruti?
Sa = G. On a 5 kattai mridangam the chapu reads around G4 (392.00 Hz), or G3 (196.00 Hz) on some phones. 4 kattai is F and 6 kattai is A.
Which stroke do I use to tune a mridangam?
The chapu (cha), played on the edge of the valanthalai. Do not use the dheem: its pitch sits roughly one to two semitones above Sa and the reading comes out wrong.
Should the thoppi be tuned to a note?
No fixed note. Keep its tension even; some players leave it near the chapu or an octave below, and the rava paste lowers it before the concert.
Can one mridangam play every shruti?
Usually not. As a guide, larger thagu drums (24–26 in) suit B to E, smaller sthaayi drums (about 22 in) F to A♯. Each drum has its own range, so follow your teacher or maker.
How do I tune a nut and bolt mridangam?
Play the chapu at each point of the rim and turn the nearest bolt with the key a little at a time, tightening to raise the pitch, until every point reads the same note.