Natural Harmonics
A harmonic is produced when you lightly touch a string at a specific point — a node — rather than pressing it to the fretboard. The touch divides the vibrating string into equal segments, producing a frequency much higher and purer than normal fretted notes.
The sound is often described as bell-like, chime-like, or crystalline. It is used for special effects, delicate melodic passages, and as the most accurate method of tuning a guitar by ear.
How to Play Harmonics
- Rest the tip of your left-hand 2nd finger directly over the 12th fret wire on the 1st string — not behind it, directly on top of the metal bar
- Pluck the 1st string firmly with your right thumb or finger
- Immediately lift your left finger away from the string as soon as you pluck
- A clear, pure bell tone should ring — one octave above the open 1st string
The most common mistake is pressing the string toward the fretboard. The touch should be so light that the string barely makes contact with your fingertip. Think of it as a whisper of contact, not a press.
Harmonic Positions
One octave above the open string. The clearest, loudest harmonic. All 6 strings have a strong harmonic here. Used for tuning and for musical effect.
One octave plus a fifth above open. Also strong. Used in tuning (the 7th fret harmonic of one string matches the 12th fret harmonic of the string below it).
Two octaves above open. Very clear. The 5th fret harmonics on adjacent strings give useful tuning references.
Two octaves plus a major third. Higher and softer. Less used musically but produces beautiful bell-like clusters when multiple strings are played together.
Tuning with Harmonics
Harmonics are the most precise way to tune a guitar by ear because the pure tones are much easier to compare than ordinary fretted notes. Use these pairs:
- 7th fret harmonic of string 6 = 12th fret harmonic of string 5 (both = A)
- 7th fret harmonic of string 5 = 12th fret harmonic of string 4 (both = D)
- 7th fret harmonic of string 4 = 12th fret harmonic of string 3 (both = G)
- 7th fret harmonic of string 3 = 12th fret harmonic of string 2 (both = B)
- 7th fret harmonic of string 2 = 12th fret harmonic of string 1 (both = E)
When two harmonics of the same pitch are played together in sequence, any tuning discrepancy creates a wavering 'beat' effect. When perfectly in tune, the beat disappears and the two tones ring together as one.
Open G Tuning (D-G-D-G-B-D)
Open G tuning re-tunes three strings so the open guitar sounds a full G major chord. Starting from standard EADGBE tuning:
- String 6: tune down from E to D
- String 5: tune down from A to G
- Strings 4, 3, 2: stay the same (D, G, B)
- String 1: tune down from E to D
In Open G, laying a straight finger barre across all strings at any fret produces a major chord. Fret 2 = A major. Fret 3 = Bb major. Fret 5 = C major. Fret 7 = D major. Slide guitar and bottleneck playing work beautifully in this tuning.
Always re-tune your guitar when switching between standard and open tunings. Never forget to retune back to standard EADGBE when returning to standard playing. Leaving a guitar in open tuning long-term is fine as long as the neck relief is checked periodically.
Open D Tuning (D-A-D-F#-A-D)
Open D produces a D major chord across all open strings. From standard tuning:
- String 6: tune down from E to D
- String 5: stays the same (A)
- String 4: stays the same (D)
- String 3: tune down from G to F#
- String 2: tune down from B to A
- String 1: tune down from E to D
Open D is slightly lower in overall tension than Open G, making it particularly suitable for acoustic slide guitar and solo fingerpicking. Joni Mitchell used Open D and related tunings for much of her most distinctive work.
What's Next?
Lesson 37 covers the guitar troubleshooting guide — how to diagnose and fix the most common guitar problems including buzzing strings, tuning instability, and strings that keep breaking.