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Best Viola Tuner? Free Strobe App for CGDA
Why the best viola tuner is a strobe
A bowed string is exactly what a strobe tuner was designed for. The bow drives the string continuously, so the tone sustains for as long as you draw the bow, and the harmonic spectrum is rich and stable. That means the strobe pattern has time to settle and the cents reading is rock-steady - far more so than on a plucked note that decays in a second or two. Needle tuners flicker by whole cents on a sustained note; the best viola tuner for orchestral players is one that shows a stable pattern you can read across a long downbow.
CGDA, and why fifths tuning matters
The viola is tuned in perfect fifths: C3, G3, D4, A4 - exactly one fifth below the violin. Because each string is a fifth from its neighbour, players check intervals by playing double-stops and listening for beats, not by reading a meter on each string in isolation. Tune A first, then tune C, G, and D against it. The 0.1-cent reading on StroboPro is steady enough to leave on a stand while you bow each string in turn.
The C string and the alto range
The viola's low C string (C3, ~130.8 Hz) is where a multi-harmonic strobe shines. StroboPro gives every harmonic its own smooth rotating ring, so you see the fundamental and its partials together; when every harmonic ring stops moving, the string is genuinely in tune across its spectrum. That matters especially on the alto C.
How to tune a viola with StroboPro
- Open the viola tuning - tap the Tap to Tune button (the one with the microphone) and allow microphone access.
- Tune the A string first, to a 440 Hz reference (or 442 Hz if your ensemble plays sharp).
- Bow the A with a long, even downbow, no vibrato. The harmonic rings should stop rotating.
- Tune D to A, then G to D, then C to G. Bow each pair as a double-stop to confirm the fifth is pure.
- Avoid vibrato while checking pitch - it modulates the note by several cents and makes any tuner read an average.
Related guides
Frequently asked questions
What notes is the viola tuned to?
The viola is tuned C3, G3, D4, A4 (CGDA) - one perfect fifth below the violin. StroboPro ships a Viola preset with those exact targets; it is also fully chromatic for scordatura. Open it directly: [viola standard tuning](https://strobopro.se/preset/viola/4-string/standard).
Should I use a clip-on tuner or a phone app for viola?
Either works. A clip-on hears only the string it touches, good in a noisy room. A phone mic hears the whole instrument, so you can play double-stops while you tune and check that the fifths are pure. StroboPro runs on either and is steadier on a sustained bowed tone than a needle tuner.
Support independent development with premium access
I’m an independent developer, and I keep the core StroboPro tuner free. Premium access to features such as cloud sync, AI tuning generation, and the custom tuning editor helps cover backend infrastructure and the tools I need to keep developing and supporting StroboPro.
You can try the full version during a no-strings-attached trial. The trial never converts automatically: when it ends, premium features are simply disabled until you actively choose an affordable subscription or a one-time purchase for lifetime premium access. The one-time purchase is available on iOS and Android, like buying the app outright; web one-time purchase support is coming soon.
Published by Applicaudia, the maker of StroboPro. Resolution figures describe the on-screen display, not lab-measured accuracy specifications. Reference pitch (440 vs 442 Hz) and interval choices vary by ensemble and tradition.
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