How to correctly tune your Guitar

There are several ways to tune a guitar. One is to use a set of pipes for all six strings. I do not recommend this since a single pipe can have the same result, and moreover alternate tunings are not covered by the 6pipes-set. The second way is to use a single pipe as already mentioned. This is usually a "A"-pipe with frequency of 440 Hz. On the guitar it matches (unison) the 5th fret of the 1st string. The third way is to use an "A"-fork. Well that's identical to a "A"-pipe and it is a matter of taste which to use. Pipes are not expensive and handy to carry with.

What about harmonics?

No! Tuning with harmonics---other than the 1st harmonic on the 12 fret which is an octave above the open string---are not correct equal-tempered tunings. The frequencies of natural harmonics (notes as found in the nature) which are based on the length of vibrating strings (1/2, 2/3, 3/4, ...) do not match the frequencies of the artificial equal-tempered tuning which is used in the western music.

Octave based tunings

A tuning is called octave based tuning when we are comparing unisons or octave intervals while tuning all the strings. Every octave based tuning tunes a guitar correctly, if it is correctly done.

Popular tuning procedure. Unison tuning

The following tuning is the most popular one and it is entirely based on unisons.

The diagram illustrates the procedure.

      e ||----|----|----|----|----|----|-
      b ||----|----|----|----|--e-|----|-
      g ||----|----|----|--b-|----|----|-
      d ||----|----|----|----|--g-|----|-
      a ||----|----|----|----|--d-|----|-
      e ||----|----|----|----|--a-|----|-
           1st       3rd       5th       
      

A better tuning

Well an even better kind of tuning is based on octaves of the same note for all the strings. You can tune all the six strings by comparing A tones at different octaves and different strings with the open 2nd string (A). This approach has the advantage that all the strings are compared to the same string (2nd) and not to each other. So errors on tuning of one string does not propagate.

Procedure:

      e ||----|----|----|----|--a-|----|----|----|----|----|----|----|...
      b ||----|----|----|----|----|----|----|----|----|--a-|----|----|...
      g ||----|--a-|----|----|----|----|----|----|----|----|----|----|...
      d ||----|----|----|----|----|----|--a-|----|----|----|----|----|...
      a ||----|----|----|----|----|----|----|----|----|----|----|----|...
      e ||----|----|----|----|--a-|----|----|----|----|----|----|----|...
           1st       3rd       5th       7th       9th           12th fret