# AI Wiki - Music - Harmonics ## Overview A vibrating string doesn't only swing as a whole. It also vibrates in halves, thirds, quarters and so on at the same time, and each of those partial vibrations adds a higher, quieter pitch on top of the note: the **overtones** or **harmonics**. Together they give a guitar its tone. Every partial vibration has **nodes**, points where the string doesn't move. Touch the string lightly at a node and you stop every vibration that would need that point to move, including the fundamental. What remains is the harmonic: a pure, bell-like, glassy tone, higher than the open note. That's all a guitar harmonic is, and every technique below is a different way of touching a node. Harmonics are used as melodic effects (bell tones in ballads and fingerstyle pieces), as [[AI Wiki - Music - Rock Music|rock]] and metal "squeals", as a tuning aid, and as a test of a guitar's intonation. ## Natural harmonics Natural harmonics are played on **open strings**: the fretting hand touches the string lightly, directly **over the fret wire** (not behind it, where you'd fret a note), you pick, and the touching finger lifts off right after so the harmonic rings. Don't press: the finger only touches. The node positions are simple fractions of the string length, and the pitch follows from the fraction: | Touch over fret | Fraction of the string | Harmonic | Sounds (above the open string) | On the low E string | | --- | --- | --- | --- | --- | | 12 | 1/2 | 2nd | one octave | E3 | | 7 (and 19) | 1/3 (2/3) | 3rd | an octave and a fifth | B3 | | 5 (and 24) | 1/4 (3/4) | 4th | two octaves | E4 | | 4 (and 9, 16) | 1/5 (2/5, 3/5) | 5th | two octaves and a major third | G#4 | | just past 3 (often written 3.2) | 1/6 | 6th | two octaves and a fifth | B4 | So the 12th-fret harmonic is the same note as fret 12 (the open string an octave up), the 7th-fret harmonic is the same note as fret 19, and the 5th-fret harmonic is the same note as fret 24. The higher the harmonic, the smaller the "sweet spot" and the quieter the result: 12 is easiest, then 7, then 5; 4 and 3.2 need precise placement. Classical teacher Douglas Niedt notes that the 4th- and 9th-fret nodes sit slightly behind the fret wire and the 3rd-fret node a few millimetres in front of it, because those frets don't fall exactly on the fractions. The 5th harmonic (fret 4) is a **pure** major third, about 14 cents flatter than the equal-tempered third on the frets, so a fret-4 harmonic never quite matches the fretted G#: that's physics, not your guitar. In tab, a natural harmonic is the fret number in angle brackets, `<12>` (also `[12]`, "N.H." or "Harm."); see [[AI Wiki - Music - Reading Guitar Tab]]. A short exercise: harmonics at fret 12 on the D, G, B and e strings, then chords of harmonics at frets 7 and 5 on the top three strings. ```chords {title: Natural harmonics at frets 12, 7 and 5} {comment: Let every harmonic ring. Fret 12 sounds D G B E an octave up; fret 7 sounds D F# B (a B minor triad); fret 5 sounds G B E two octaves up} {start_of_tab} e|----------------------<12>---<7>----<5>----| B|---------------<12>----------<7>----<5>----| G|--------<12>-----------------<7>----<5>----| D|-<12>--------------------------------------| A|-------------------------------------------| E|-------------------------------------------| {end_of_tab} ``` **Technique tips.** Pick closer to the bridge than usual: the harmonic speaks better there. Touch with the fleshy pad, exactly over the wire. Too much pressure mutes the string (a dead thud); too little lets the open string sound through. Lift the finger a split second after the pick strikes. On [[AI Wiki - Music - Electric Guitar|electric guitar]], the bridge pickup and a bit of gain make harmonics much louder ([[AI Wiki - Music - Guitar Amps and Tone]]). ## Artificial harmonics Natural harmonics only give the pitches of the open strings' overtones. **Artificial harmonics** move the whole system: fret a note, and the string is shorter, so every node moves up by the same number of frets. The 12th-fret node of a note fretted at 5 is at fret 17. The classic method, from [[AI Wiki - Music - Classical Guitar|classical guitar]]: fret the note with the fretting hand; lay the **picking hand's index finger** lightly on the string over the fret **12 frets higher**; pluck behind it with the thumb or the ring finger; lift the index a moment later. Fretted G at the 5th fret of the D string plus a touch at fret 17 gives a G an octave up, with the harmonic's bell tone. Doing this for every note of a melody or chord, the way Chet Atkins, Lenny Breau and Tommy Emmanuel do, is called **harp harmonics** when harmonics alternate with ordinary plucked notes to make a harp-like cascade. It's a [[AI Wiki - Music - Fingerpicking|fingerstyle]] technique; it also works with a pick held between thumb and middle finger, leaving the index free. ## Pinch harmonics The rock version. Pick the note with the pick held so that the **side of the thumb catches the string immediately after the pick**. The thumb touches a node for an instant, kills the fundamental and leaves a high overtone: the "squeal" of Billy Gibbons, Zakk Wylde (who Wikipedia names as best known for it) and countless metal players. What decides which harmonic you get is **where along the string you pick**: move the picking hand a few millimetres toward the neck or the bridge and the squeal jumps to a different overtone. Practical tips: - Choke up on the pick so only a sliver shows, and dig in a little. - Find the spot over or near the bridge pickup; scan along the string until it squeals. - Use the bridge pickup and plenty of gain (and some compression); pinch harmonics on a clean tone are faint. See [[AI Wiki - Music - Guitar Effects]]. - Add vibrato or a bend once it speaks ([[AI Wiki - Music - Guitar Lead Techniques]]). In tab they're marked "P.H." above the fret number. In [[AI Wiki - Music - Metal Music|metal]] they're used to accent a [[AI Wiki - Music - Muting Techniques|palm-muted]] riff ([[AI Wiki - Music - Metal Rhythm Guitar Techniques]]). ## Tapped harmonics Popularized by Eddie Van Halen as an extension of tapping. Fret a note (or a chord, or nothing), then **tap the string sharply with a picking-hand finger right on the fret wire 12 frets higher** and bounce off. The tap excites the string at a node. Wikipedia's example: hold the 3rd fret, tap the 15th. Over open strings, tapping at fret 12 gives the same harmonics as natural ones; tapping at 5, 7 or 17 gives others. Tapped harmonics over a held chord ("chord harmonics") sound like a music box. How harmonics look in tab, on one fretted note (fret 5 of the G string is C): a pinch harmonic, then an artificial harmonic touched at fret 17, then a tapped harmonic at fret 17. Books write the touched or tapped fret in parentheses or as a small number above. ```chords {title: Harmonic markings in tab} {comment: Fret 7 picked normally, then with a pinch harmonic; fret 5 with an artificial harmonic (touch fret 17); fret 5 with a tapped harmonic (tap fret 17)} {start_of_tab} P.H. A.H. T.H. e|---------------------------------------------------------| B|---------------------------------------------------------| G|-7-------7---------------5(17)-----------5(17)-----------| D|---------------------------------------------------------| A|---------------------------------------------------------| E|---------------------------------------------------------| {end_of_tab} ``` ## Tuning with harmonics Harmonics ring without your fretting hand, so you can compare two strings while turning a tuning peg, and hear the **beats** (a wobble in volume) that disappear when the two pitches match. The common method: - Low E 5th-fret harmonic = A string 7th-fret harmonic (both E4). - A 5th = D 7th, D 5th = G 7th. - Low E 7th-fret harmonic = open B (both B3), or B 5th-fret harmonic = high E 7th-fret harmonic. - Low E 5th-fret harmonic = open high E (both E4): a pure two-octave check. The catch: the 7th-fret harmonic is a **pure fifth** (a 3:2 ratio, about 702 cents) and the frets are in equal temperament (exactly 700). Each 5th/7th match leaves a fourth about 2 cents narrower than the frets want, and the error adds up string by string: by the G string you can be around 6 cents flat of the low E. That's why guitar teachers treat the method as a quick check, not a replacement for a tuner or for checking fretted octaves against chords you play. Octaves (fret 12 and fret 5 harmonics) don't have this problem. The **12th-fret harmonic versus the fretted 12th-fret note** is also the standard intonation test: if the fretted note is sharp or flat compared with the harmonic, the saddle needs adjusting. See [[AI Wiki - Music - Guitar Setup and Maintenance]]. In alternate tunings, harmonics are a quick way to check a retuned string (in Drop D, the low string's 12th-fret harmonic matches the open D string; see [[AI Wiki - Music - Alternate Tunings]]). ## Harmonics in music - **Bell tones in arrangements**: natural harmonics at fret 12 to close a phrase, or a melody picked out in harmonics. Steve Howe opens Yes's "Roundabout" with harmonics; the end of many fingerstyle pieces is a harmonic chord at fret 12. See [[AI Wiki - Music - Fingerstyle Arranging]]. - **Squeals**: pinch harmonics in blues-rock, hard rock and metal, usually on a bent or vibratoed note. - **Pads and textures**: harmonics through delay and reverb ([[AI Wiki - Music - Guitar Effects]]). - **Slide and steel**: slide players use natural and artificial harmonics too; see [[AI Wiki - Music - Slide Guitar]]. ## How to practise 1. Natural harmonics at fret 12 on all six strings, until every one rings clearly. Then fret 7, then fret 5. 2. The tab exercise above, letting all notes ring together. 3. Tune by harmonics, then check with a tuner and note how far off each string ended up. 4. Artificial harmonics: fret a C [[AI Wiki - Music - Major Scale|major scale]] on the B string and touch 12 frets above each note. 5. Pinch harmonics: on the G string at fret 7 with gain, scan the picking position in millimetre steps until it squeals; then find a spot that works on every string. 6. Tapped harmonics: hold an open E chord, tap at fret 12 across the strings, then tap 12 frets above a G chord's fretted notes. ## Common mistakes - **Touching behind the fret** (where you'd fret a note) instead of right over the wire. - **Pressing.** A harmonic needs a touch, not a fret. - **Leaving the finger on too long** (muffles the harmonic) or **lifting too early** (the open string sounds). - **Picking near the neck**, where harmonics are weak. - **Blaming the guitar** for a fret-4 harmonic that doesn't match the fretted note: pure thirds are flatter than tempered ones. ## Key Points - A harmonic sounds when the string is touched lightly at a node, a fraction of its length: 1/2 (fret 12), 1/3 (fret 7), 1/4 (fret 5), 1/5 (fret 4). - Fret 12 = octave, fret 7 = octave plus fifth, fret 5 = two octaves, fret 4 = two octaves plus a major third. - Artificial harmonics: fret a note, touch 12 frets higher with the picking hand, pluck behind it. - Pinch harmonics: the thumb grazes the string right after the pick; the picking position decides the pitch; gain and the bridge pickup help. - Tapped harmonics: tap the fret wire 12 frets above the fretted note. - Tuning with 5th/7th-fret harmonics leaves about 2 cents of error per string pair; use octaves or a tuner to confirm. - The 12th-fret harmonic against the fretted 12th note is the intonation check. ## Open Questions - Which songs in Sébastien's repertoire would benefit from a harmonic ending or a harmonic melody? - How well do pinch harmonics work on an acoustic guitar without amplification? - Are harp harmonics worth learning at this stage, or after basic [[AI Wiki - Music - Fingerpicking Patterns|fingerpicking patterns]] are automatic? ## References - String harmonic, Wikipedia: https://en.wikipedia.org/wiki/String_harmonic - Harmonic, Wikipedia: https://en.wikipedia.org/wiki/Harmonic - Pinch harmonic, Wikipedia: https://en.wikipedia.org/wiki/Pinch_harmonic - Guitar/Harmonics, Wikibooks: https://en.wikibooks.org/wiki/Guitar/Harmonics - Douglas Niedt, "Guitar Technique Tip: Harmonics": https://douglasniedt.com/Tech_Tip_Harmonics.html - Perfect fifth (pure vs equal-tempered fifth), Wikipedia: https://en.wikipedia.org/wiki/Perfect_fifth ## Related - [[AI Wiki - Music - Guitar Lead Techniques]] - [[AI Wiki - Music - Reading Guitar Tab]] - [[AI Wiki - Music - Intervals]] - [[AI Wiki - Music - Guitar Setup and Maintenance]] - [[AI Wiki - Music - Alternate Tunings]] - [[AI Wiki - Music - Guitar Amps and Tone]] - [[AI Wiki - Music - Guitar Effects]] - [[AI Wiki - Music - Fingerpicking]] - [[AI Wiki - Music - Fingerstyle Arranging]] - [[AI Wiki - Music - Slide Guitar]] - [[AI Wiki - Music - Metal Music]] - [[AI Wiki - Music - Metal Rhythm Guitar Techniques]] - [[AI Wiki - Music - Hybrid Picking]] - [[AI Wiki - Music - Percussive Fingerstyle]]