Let’s consider standard tuning of C2 D2 F2 G2 A2 C3 D3.

Absolute tuning would be if you tuned your instrument to exactly what standard tuning specifies, so the first string is C2, second is D2, third is F2, and so on.

Relative tuning would be if your instrument was tuned such that the distance between the strings are the same as the indicated tuning but the notes may be different. So, in standard tuning, the distance between the first and second string is a whole step (C2 → C#2 → D2), between the second and third strings is one and a half steps (D2 → D#2 → E2 → F2), third to fourth string is a whole step (F2 → F#2 → G2), fourth to fifth string is a whole step (G2 → G#2 → A2), fifth to sixth is one and a half steps (A2 → A#2 → B2 → C3), and sixth to seventh string is a whole step (C3 → C#3 → D3). This means, I could have my instrument tuned a half step flat, so B1 C#2 E2 F#2 G#2 B2 C#3, and the song will still sound okay because the distance between the strings are a whole step, one and a half step, whole step, whole step, one and a half step, and a whole step, which is the same as the distance between the strings in the standard tuning of C2 D2 F2 G2 A2 C3 D3.

There are many who will tune the fifth string to A=440Hz, as per western modern standard pitch. As most people play the qin solo, it generally doesn’t matter if your qin is tuned to A=440Hz or to another frequency, and it doesn’t matter if the instrument is tuned absolutely or relatively.

Simply pluck the string with your right hand (play an open string), the tuner will tell you what note is being played, and by comparing that note to the desired note you either tighten or loosen the string. To tighten, rotate the pegs clockwise, to loosen, rotate the pegs counter-clockwise.

If you are just starting out, I would recommend you tune using a tuner and tune the instrument to standard tuning.

If you do not have a physical tuner handy, there are multiple tuning apps available in the app store on Androids and iPhones.

Depending on which string you opt as your reference, you would then use a harmonic pair to use that string to tune the next, and then select another harmonic pair to use the newly tuned string to tune the following string, and so on until all your strings are tuned.

For example, if I select the fifth string as my reference:

1. Use the 5th string to tune the 7th string by using the green harmonic pair.

2. Use the 7th string to tune the 4th string by using the blue harmonic pair.

3. Use the 4th string to tune the 6th string by using the orange harmonic pair.

4. Use the 6th string to tune the 3rd string by using the purple harmonic pair.

5. Use the 3rd string to tune the 1st string by using the red harmonic pair.

6. Use the 4th string to tune the 2nd string by using the yellow harmonic pair.

If I were to select the first string as my reference:

1. Use the 1st string to tune the 3rd string by using the red harmonic pair.

2. Use the 3rd string to tune the 6th string by using the purple harmonic pair.

3. Use the 6th string to tune the 4th string by using the orange harmonic pair.

4. Use the 4th string to tune the 7th string by using the blue harmonic pair.

5. Use the 7th string to tune the 5th string by using the green harmonic pair.

6. Use the 4th string to tune the 2nd string by using the yellow harmonic pair.