How to tune a viola and cello

Both are tuned C G D A in fifths. The viola sits a fifth below the violin, the cello an octave below the viola. Exact pitches, and what changes when the C string gets low.

July 29, 2026

Viola and cello share the same set of letters, C G D A, tuned in perfect fifths. The cello sits exactly one octave below the viola.

Viola

A viola is a fifth below a violin. Its top three strings are the violin’s bottom three, and the C string is new.

Cello

Same letters, one octave down from the viola. The A here is 220 Hz, an octave below the 440 Hz A that the violin and viola tune to, which is worth knowing if you are working from a tuning fork.

Reference the A first

Both instruments tune from the A string, same as the violin. Get that right against the tuner or a fork, then work outward.

Use the fine tuners for small corrections and the pegs only when you have to. On a cello especially, pegs need to be pushed in toward the scroll as you turn or they will not hold. Many cellos have fine tuners on all four strings for exactly this reason, and if yours only has one on the A, adding them to the others is a cheap and worthwhile job.

The C string is where tuners struggle

The cello’s C2 at 65.41 Hz is low enough that its fundamental is weaker than several of its own overtones. That is the condition where a naive pitch detector reports the octave above and tells you you are a full twelve semitones flat.

If a tuner has ever insisted your C string needed to come up dramatically when it sounded fine, that is what happened. See octave errors.

Bowing helps considerably. A bowed C sustains and gives the detector a stable signal, where a plucked one is over before it has settled.

Fifths against a piano

Tuning each string as a pure fifth from the one beside it will leave your C flatter than a piano’s C. Three stacked pure fifths accumulate enough error to hear. If you are playing with a fixed-pitch instrument, tune every string to the tuner individually rather than chaining fifths by ear. The temperament guide covers why the two systems disagree.