Rosin is a tuner app designed for string instruments. It supports violin, viola, cello, and double bass modes. It also offers options such as equal temperament / just intonation, A=440 Hz or 442 Hz calibration, reference tone playback, and note-naming settings.

1. First Time Opening the App: Check These Settings First

After opening Rosin, do not rush to tune immediately. First, check these four things.

First, allow microphone access. The tuner needs your phone’s microphone to hear the violin sound; otherwise, the display will not respond correctly to pitch.

Second, choose Violin as the instrument. Rosin has different modes for different string instruments. For violin, use Violin mode, because the four open strings of the violin are:

Violin String	Tuner Note Name	Fixed-Do Solfège
G string	G	Sol
D string	D	Re
A string	A	La
E string	E	Mi

Third, set the reference pitch to A = 440 Hz at first. Unless your teacher, piano, or ensemble requires A=442, A=440 is usually the safest choice for beginner practice.

Fourth, beginners should start with Equal Temperament. If you are just tuning open strings and practicing with method books, equal temperament is easier to understand. Rosin also supports Just Intonation, which is more useful later when practicing ensemble playing, harmony, and pure fifths.

2. Remember This Tuning Order First

A common violin tuning order is:

A → D → G → E

That means you tune the A string / La first, then the D string / Re, then the G string / Sol, and finally the E string / Mi.

The reason is that the A string is often used as the reference pitch. Many teachers, pianos, and ensembles also give the A first.

However, when memorizing the open strings, you can also use the low-to-high order:

G D A E = Sol Re La Mi

Do not mix up these two orders:

String-name memorization: G D A E / Sol Re La Mi Actual tuning order: A D G E, then check all strings again

3. Basic Tuning Steps

Place your phone not too far from the violin, preferably on a music stand or table. Make sure the microphone is not blocked. The quieter the environment, the better.

First, gently play the open A string. Rosin should display A. If you use fixed Do, you can directly think of A as La. Do not add an extra mental step of “A equals La.”

A tuner usually shows three types of information:

Display	Meaning	What to Do
Flat / too low	The pitch is too low	Raise the pitch
In tune / centered	The pitch is correct	Stop adjusting
Sharp / too high	The pitch is too high	Lower the pitch

For beginners, use the fine tuners first instead of turning the pegs immediately.

You can remember the fine tuner direction like this:

Situation	Fine Tuner Direction
Pitch too low	Turn clockwise to raise the pitch
Pitch too high	Turn counterclockwise to lower the pitch

Turn only a little each time, then play the open string again to check. Do not make large adjustments while bowing hard, because it is easy to overshoot.

4. How to Tune the Four Strings One by One

1. A String: A / La

Play the open A string. Rosin should display A. In your mind, directly sing:

La

If it shows A but is too low, tighten the fine tuner slightly. If it shows A but is too high, loosen the fine tuner slightly.

2. D String: D / Re

Play the open D string. Rosin should display D. In your mind, directly sing:

Re

Be careful not to accidentally play the neighboring A string. Beginners can first pluck the string to check, then bow it.

3. G String: G / Sol

Play the open G string. Rosin should display G. In your mind, directly sing:

Sol

The G string is thicker, so the app may respond a little more slowly than with the E string. Use a steady bow speed and make sure the sound is not too soft.

4. E String: E / Mi

Play the open E string. Rosin should display E. In your mind, directly sing:

Mi

The E string is very thin, so be especially careful when tuning it. Beginners should try to use the fine tuner rather than turning the E-string peg too much.

5. Always Check Again After Tuning

After tuning A, D, G, and E, do not start practicing immediately. Check again from low to high:

G → D → A → E Sol → Re → La → Mi

When you tune one string, the tension of the whole instrument may change slightly, so strings that were already tuned may shift a little.

During the final check, do not only look at the tuner. Also use your ear to remember the feeling of the four open strings:

G / Sol: lowest and thickest D / Re: one string higher than G A / La: common reference pitch E / Mi: highest and brightest

6. About Note-Name Display: Recommended Setting

Since you are practicing fixed Do, I recommend using the C D E F G A B note-name system in Rosin, if such a setting is available. Do not rush to switch everything to solfège.

The reason is that tuners, method books, staff notation, and teachers usually refer to the violin strings as G string, D string, A string, and E string. What you want to practice is seeing the letter and directly hearing fixed Do:

Tuner Display	Sing Directly in Your Mind
G	Sol
D	Re
A	La
E	Mi

Do not think:

G → translate → Sol

Instead, train yourself so that:

When you see G, Sol sounds directly in your mind.

If the app’s note-naming setting allows different display systems, you can occasionally switch to solfège to reinforce memory. But for normal tuning, I still recommend keeping letter names, because they are most consistent with violin method books, string names, and teacher instructions.

7. How to Use Reference Tones

Rosin provides reference tones that play standard pitches for you. This feature is very useful for training your ear instead of constantly watching the needle.

Practice like this:

Play the A reference tone. Sing La along with it. Then play your A string. Only then look at the tuner to check.

You can also do this for one minute every day:

Hear A → sing La → play A Hear D → sing Re → play D Hear G → sing Sol → play G Hear E → sing Mi → play E

This way, the tuner is not only a calibration tool, but also an ear-training tool.

8. When to Use Equal Temperament and When to Use Just Intonation

At the beginner stage, remember this simply:

For solo practice, method books, and playing with piano: use Equal Temperament.

For practicing open-string fifths, ensemble playing, and pure harmony: you can try Just Intonation.

Rosin supports switching between Equal Temperament and Just Intonation. But right now, the most important thing is not studying tuning systems; it is first getting the four open strings reliably in tune. For most beginner practice, equal temperament is enough.

9. Common Questions

1. What if the app displays a different note from the string I am tuning? Usually this means you played the wrong string, the environment is too noisy, the sound is too weak, or the string is very far from the correct pitch. First make sure you are playing an open string and not touching it with the left hand. Move closer to the phone microphone and play steadily again.

2. What if the needle keeps shaking? Use a steadier bow. Do not press too hard at the beginning, and do not play too softly. You can first pluck the string to check the approximate pitch, then use the bow for fine adjustment.

3. Should I stare at the tuner all the time when practicing intonation? No. It is fine to look at the tuner when tuning open strings. But when practicing finger intonation, it is better to listen first, sing first, play first, and only then check with the tuner. Otherwise, your eyes will become dependent on the tuner instead of your ears developing pitch awareness.

4. Can I use the fine tuner if the string is very far out of tune? If it is only a little off, use the fine tuner. If it is far off, you may need to turn the peg. Beginners should ask a teacher to demonstrate peg tuning, especially because the E string can easily be overtightened.

10. The Best Daily Routine for You

Use Rosin for three minutes before each practice session:

Minute 1: Tune A → D → G → E.

Minute 2: Check the open strings G D A E, and in your mind sing Sol Re La Mi.

Minute 3: Sing first without looking at the app, then play Sing Sol → play G. Sing Re → play D. Sing La → play A. Sing Mi → play E. Then check with Rosin at the end.

This way, you are not only tuning the violin. You are also training yourself to:

See G/D/A/E → directly hear Sol/Re/La/Mi → then play it with your hands.