Viola Tuner — CGDA Standard Tuning

A viola is tuned in perfect fifths to CGDA: C3, G3, D4 and A4 from the lowest string to the highest, with A4 = 440 Hz as the usual reference. It uses the same note names as the cello, one octave higher, and it sits a fifth below the violin.

How to use it

1. Start the tuner. Press Start Tuner (Microphone) and grant access; the analysis stays on your device.
2. Bow halfway between the bridge and the fingerboard. Contact right on the bridge excites a thin, harmonic-heavy tone and contact over the fingerboard gives a soft, airy one; the middle strip gives the viola’s low C its strongest fundamental.
3. Sweep one string at a time with a slow, even stroke. The viola’s C and G speak later than a violin’s strings — hold the bow through the note instead of judging the display on the attack.
4. Touch the idle strings with a left-hand finger. The C and G ring under a D or A being tuned; a feather touch damps them without pressing them to the fingerboard.
5. Pegs for the big moves, fine tuners for the last cents. Seat a peg with gentle inward pressure, then finish with the fine tuner so the string does not slip back.
6. Approach the target from below. If a string is sharp, ease it under the note and raise it back up — the viola’s thick C holds pitch better that way.
7. Test the fifths in pairs. Bow C with G, then G with D, then D with A. A pure fifth is beatless; a slow throb means the upper string of the pair needs the adjustment.
8. Set the reference to match the room. Leave it on A4 = 440 Hz unless your orchestra tunes to 442, in which case pick that chip before the first bow stroke.

Viola string frequencies

Counted from the player’s side, the 4th string is the viola’s lowest and most massive, and the 1st is the A at the top.

String	Note	Frequency (A4 = 440 Hz)
4th (lowest)	C3	130.81 Hz
3rd	G3	196.00 Hz
2nd	D4	293.66 Hz
1st (highest)	A4	440.00 Hz

Viola, violin and cello: same letters, different octave

The most common confusion about the viola is not its own tuning but its relationship to the cello. Both instruments are tuned CGDA — and the viola’s is exactly one octave above the cello’s:

Instrument	Lowest string	Tuning	Held
Violin	G3 (196.00 Hz)	GDAE	Under the chin
Viola	C3 (130.81 Hz)	CGDA	Under the chin
Cello	C2 (65.41 Hz)	CGDA	Between the knees, on an endpin

• A shared tuning does not mean a shared pitch. The viola’s C3 is 130.81 Hz; the cello’s C2 is 65.41 Hz, half the frequency and an octave lower. The same finger pattern produces the same note names on both instruments, but a viola sounds an octave above a cello playing the same line.
• The preset matters. If the tuner is set to cello while you play a viola, the C string can read as C2 — a real note, but the wrong octave for the instrument. Check that the C string card reads C3 before you tune.
• The instruments look different even when the tuning does not. The viola is the largest instrument held under the chin; the cello stands on an endpin and is played seated. If someone is unsure which they have, the posture settles it.
• The clefs differ. Violas read alto clef, which puts middle C on the middle line of the staff. Cellos read bass clef, with tenor and treble clefs used for higher passages. The clef changes what you read, not what you tune.
• The viola is the middle voice of the string quartet. In a quartet of two violins, viola and cello, the viola sits between the violins above and the cello below. Its CGDA tuning puts it a fifth below the violin and an octave above the cello, which is exactly where that middle part lives.

The viola’s body and string tension

A viola is not simply a scaled-up violin. The relationship between its size and its tuning is the instrument’s central design compromise:

• The body is larger, but not proportionally larger. A violin body is roughly 14 in (35.5 cm) long and a viola’s is commonly around 15.5 to 16.5 in (39 to 42 cm). For CGDA at violin proportions, an instrument would need to be considerably bigger still.
• The C string carries the compromise. Because the body is smaller than the tuning would ideally want, the low C string is thick and under high tension, and it needs a well-made instrument to speak freely. Smaller violas in particular can sound weak or slow on the C string.
• The strings are heavier than a violin’s. Thicker strings at lower pitch need more tension, and the viola’s four strings are all heavier than their violin counterparts.
• The sound is darker and more covered. The viola’s lower register and heavier strings give it a tone that is often described as darker, warmer or more veiled than a violin’s. That character is why it is used for inner voices and for music that wants weight without brightness.
• Size affects playability as well as sound. A larger viola has more low end but longer string stops and wider stretches for the left hand. Players choose a size that balances the two, which is why violas vary more in size than violins do.

A442 and other references

A4 = 440 Hz is the default here, but a viola often ends up tuning higher in practice: orchestras in Japan and across continental Europe frequently set the house pitch at A442, while early-music groups may ask for A415 or A430. The chips above cover that whole span.

• A442 raises every target by about 0.45 %. The strings remain in perfect fifths relative to each other; the whole instrument sits slightly higher.
• A mismatch shows up as a uniform error. A viola left on 440 while the ensemble plays 442 reads flat on every string, so set the chip first.
• Ask, don’t guess. Rehearsal pianos, auditions and conductors each have their own A; a quick question saves a retune.

Accuracy and limits

• The C string is the lowest note on this page and the least certain to read. It is the instrument’s weakest-speaking string and the one a small microphone picks up least strongly. Bow it with a long, even stroke, hold the note, and check it against its octave harmonic instead of trusting a single frame.
• A jumping display means the fundamental is hiding. If the reading hops to C4 while you bow the C string, its overtones are louder than its fundamental. Settle the bow, keep the note going, and compare what you see against the C3 card rather than a single frame.
• The viola is quieter than a violin. Its lower register does not reach a distant microphone as well. Tune close to the device, and in a full section tune before the room fills with players if you can.
• The open strings ring together. The C and G strings share overtones and will sound under a D or A being tuned. Damp them with a light left-hand touch.
• A wrong preset can look like a right answer. The cello preset also shows C, G, D and A, so an octave error can pass unnoticed. Check the octave on the string card — C3 for the viola, C2 for the cello.
• Pizzicato gives a shorter reading. The note dies quickly. Bow when you can, or pluck again and watch the display rather than judging one frame.
• Temperature and humidity move the instrument. A cold viola arrives flat; pegs can slip in dry weather. Give it a few minutes of playing to settle, and glance at the display again later in the session.
• Every string flat by the same amount? Blame the reference. Uniform readings point at a mismatched A rather than four slipping pegs, so check the chips before you touch anything.

Safety

• The bridge is held in place by string tension, and the soundpost by friction. Never remove all four strings at once; replace them one at a time so the instrument keeps its tension and the bridge stays seated.
• Raise pitch in small steps. A viola string taken from slack to pitch in one motion can snap; nudge the peg and check the reading as you go.
• Never force a peg. A peg that will not turn is binding, and forcing it can crack the pegbox. Ease it free instead.
• C3, not C2, is the viola’s target. The C string belongs at 130.81 Hz; an octave higher would double its tension, which is more than the instrument and the string are made for.
• A bottomed-out fine tuner cannot sharpen further. Back it off, take the string near the note with the peg, then finish on the tuner instead of forcing the screw.
• Support the instrument while tuning. A viola is larger and heavier than a violin. Keep it properly supported on the shoulder or in your hands rather than pulling on a peg with the instrument unsupported.
• Watch the bridge after tuning. If it has tipped forward or sits off centre, release some tension and nudge it upright, or have a luthier look at it.
• Protect your hearing. A viola under the ear is loud, and the lower register carries. Take breaks during long sessions.