Vietnamese bamboo flute tuner (sáo trúc)
The sáo trúc (or sáo ngang) is Vietnam’s transverse bamboo flute: one blowing hole, six finger holes and nothing to turn or slide. Each flute has a fixed key, named in Vietnam after the note you get with every finger hole covered, blown softly. A flute that gives C there is a sáo Đô, and since a tuner reads that note as C5, players call it a sáo C5.
Sáo trúc keys: all-holes-closed note and octave
A sáo trúc is named after the note it plays with every finger hole closed and blown softly; the same fingering blown harder gives the octave. Scientific pitch (middle C = C4), equal temperament at A4 = 440 Hz.
| Key | All holes closed | Hz | Octave | Hz |
|---|---|---|---|---|
| Sáo Đô C5 | C5 | 523.25 | C6 | 1046.50 |
| Sáo Si giáng B♭4 | B♭4 (A♯4) | 466.16 | B♭5 (A♯5) | 932.33 |
| Sáo La trầm A4 | A4 | 440.00 | A5 | 880.00 |
| Sáo Sol trầm G4 | G4 | 392.00 | G5 | 783.99 |
| Sáo Fa trầm F4 | F4 | 349.23 | F5 | 698.46 |
| Sáo Rê cao D5 | D5 | 587.33 | D6 | 1174.66 |
Sáo Trúc Hoàng Anh — “Sáo trúc cho người mới” (key naming, C5 on a tuner)
How to use it
- Tap Turn on microphone and pick the key marked on your flute under Profile (default: sáo Đô C5).
- Cover all six holes (all ten on a 10-hole flute) and blow a long, soft, steady note. You’ll see the actual note, its frequency and the cents off target.
- Keep the fingering, blow faster with firmer lips and jump to the second register: the note should land an octave higher, for example C5 to C6.
- Not sure of the key? Choose Free chromatic, close every hole and blow softly: the note and octave shown are your flute’s key.
Help and explanations
The number is the octave in scientific pitch notation, where middle C is C4. Six common keys are preset, each with two targets: the all-holes-closed note blown softly and the same fingering overblown, one octave up.
Sáo trúc keys: what C5, B♭4 and G4 mean
Every key follows the same rule as the C5. A sáo Si giáng B♭4 gives B♭4 with all holes closed (most tuners, this one included, show it as A♯4: same note, 466.16 Hz). La trầm gives A4 = 440 Hz, Sol trầm G4, Fa trầm F4 and Rê cao D5; the “cao” matters, because a low Rê trầm in D4 also exists.
Vietnamese teachers usually start beginners on the C5, whose holes are comfortably spaced. Low G4 and F4 flutes have wide bores and widely spaced holes that new hands struggle to seal, and the D5’s holes are tightly packed. A typical sáo is roughly 40–55 cm long, but don’t guess the key with a ruler: blow and measure.
Why “bamboo flute in C” is ambiguous
Chinese dizi and Indian bansuri are usually named after the note with the top three holes covered, a perfect fourth above the all-closed note, so a Vietnamese sáo C5 would be an “F” flute there. Yet some bansuri and Hmong flutes sold in English are labelled by their lowest note, so “key of C” alone doesn’t tell you what you’ll hear.
The check is the same for all of them: cover every hole, blow softly and read the note. To tune a bansuri to your own Sa, use the bansuri tuner.
Cảm âm, registers and what a tuner can’t fix
Vietnamese songbooks use cảm âm, a movable-do notation tied to the fingering: all holes closed is always Đô, then Rê, Mi, Fa, Sol, La, Si as you open holes from the bottom up. On a C5 flute Đô = C5; on a G4 flute Đô sounds G4 and Rê sounds A4, so G4 on the tuner is correct. “Đô 1, Đô 2” or “C1 to C3” in method books are the flute’s own registers, not tuner octaves: on a sáo C5, Đô 2 reads C6.
There is nothing to tune on a sáo: you pick the flute that suits the song, and only a maker fine-adjusts it with the stopper (rush pith or soft wood) in the head. Use this page to check a flute before buying and to train your embouchure. The C5 scale profile covers C5 to C6 with six-hole fingering; on handmade flutes Fa and Si can sit a few cents off, and half-holed sharps and flats are rarely exact. A 10-hole sáo plays all twelve notes: check them in free mode.
Tips
- Warm the flute up with a few long notes before measuring: a cold flute tends to play flat.
- Blowing too hard in the first register pushes the pitch sharp; if the needle sits right of centre, soften and steady your air before blaming the flute.
- The second register on bamboo doesn’t always give a perfect octave; a few cents off is normal. Some methods play Đô 2 with all holes closed except the top one.
Frequently asked questions
What key is a C5 bamboo flute?
A sáo Đô: with all six holes closed and blown softly it sounds C5, 523.25 Hz at A4 = 440 Hz, one octave above middle C.
How do I find the key of my bamboo flute?
In free mode, cover every hole and blow softly. A4 on screen means a La trầm A4; A♯4 means a Si giáng B♭4 (same pitch, 466.16 Hz).
Is a sáo C5 the same as a bamboo flute in C?
Not necessarily. By dizi and bansuri naming it would be an F flute, while some sellers label by the lowest note. Close every hole and check.
Can you tune a Vietnamese bamboo flute?
Not like a string instrument: the bore and hole positions set the key. The tuner shows how far off you are; what you can adjust is air speed and lip position.
Which bamboo flute key is best for beginners?
For the sáo trúc, C5. Lower keys such as G4 and F4 need bigger hands, and F4 takes a lot of air.
Do I need a tuner app?
No. Open this page, allow the microphone and play; the sound is analysed right in your browser.