The tuning method is typical to that of any other musical instrument. It is a matter of having a tone of reference (typically a tuning fork is used with A) and start with the top string. Have a look at the instructional video below by Cuatrista Darwin Medina on how to tune your Cuatro
Herewith also a demonstration and tuning session by Adrian Toro…for this one please remember to turn on your Subtitles:
The tuning needs to be as follows:
Once the top string is tuned being A, then the second string can be tuned by playing the A string on the 5th fret which is D. The second string should be tuned so that it is aligned with the D string.
The next step tuning the 3rd string needs to sound like the 2nd string on the 4th fret. This is the famous F#. And the last step is to tune the 4th string by using the 1st string on the 2nd fret being B.
The tuning should sound like (a traditional reference) Cam-Bur-Pin-Ton. Very traditional and sounds just like a tuned Cuatro. At this point you may have noticed that unlike conventional instruments like a guitar, the thickness of the strings does not follow a descending pattern. The thinnest and highest string is the 3rd string being F# and the last string is essentially as low as the first one. Don’t worry, it is supposed to be like this! This allows for the sounds to be in sync whether you are strumming upwards or downwards. Give it a try by strumming up and down and you will see what we mean!