Your ear becomes better at hearing whether two pitches match through repetition. At first, you may hear a pulsing or wavering sound when notes are close but not equal.
Relative tuning can make the strings match each other even if the whole guitar is slightly sharp or flat. For playing with other musicians, you still need one correct reference pitch.
Tuning by ear is a comparison task. You need one trustworthy reference pitch, then you adjust the remaining strings until their relationships match the tuning you want.
Reference note
Use a tuner, tuning fork, piano or reliable audio tone for one string, commonly low E or A.
The fifth-fret method has one exception
In standard tuning, the fifth fret of a string usually matches the next open string. The exception is the G string: its fourth fret matches the open B string. The fifth fret of B then matches the high E as usual.
Beat frequency reveals small differences
When two nearly matching pitches sound together, you may hear a slow pulsing or wavering. The pulses become slower as the pitches approach each other and disappear when they match closely.
Octave checking
Open strings can also be compared with octave notes elsewhere on the fretboard. This helps confirm the result.
Tune and check the result
- Let each reference note ring clearly.
- Adjust the target string, not the reference string.
- Listen for the pulsing to slow down.
- Practise one comparison at a time rather than rushing through all six.
- Tune the low E from a reliable tuner, piano or reference recording.
- Use matching fretted and open notes to tune the remaining strings, then verify every string with a tuner while developing your ear.
When the guitar still feels wrong
Every string matches, but the guitar is wrong with a backing track
Your first reference note was not at concert pitch. Relative tuning preserves the error across all strings.
You cannot tell whether to tighten or loosen
Move the tuning peg a tiny amount and listen whether the beating becomes faster or slower. Reverse direction if it gets worse.
Errors accumulate across the strings
Each comparison can introduce a small mistake. Return to the original reference and use harmonics or a tuner to check the complete result rather than trusting only a chain of relative comparisons.