Rings, plings and harmonics. Paul Colbert maps their positions on the average six-string.

Harmonics come upon us like certain, vision-damaging, auto-motive actions discovered in the bath. We think, we're the first to find them the learn the rest of the world has been doing it better, longer and for years. Youth is painful.

So chances are you've already located some of these high, bell-like non-notes, you may even be ludicrously accomplished at producing them from thin air. Therefore this investigation into the world of the harmonic will be divided into sections. Skip the early stages, start where it gets interesting for you.

The Physics

At the risk of being obvious, a struck string will vibrate and sound one, main frequency — the fundamental. If you imagine the string as a skipping rope — and with some guitars I've played this is surprisingly unchallenging — the shape of the vibration would be akin to viewing the rope sideways on. It's fixed at the two ends but in the middle goes all the way up and all the way down. (See fig 1.)

Lower in volume beneath the fundamental (though essential in determining the tone of an instrument) are the harmonics.

These are other frequencies which fit inside the rope (ie: the ends still don't move — figs 2 and 3 for yes and no).

When the frequency fits exactly twice the low level note is an octave higher than the fundamental, and is referred to as the first harmonic. When three fit precisely, the note is an octave and a half (octave and a fifth) higher and is the second harmonic. Four equals two octaves higher, and so on.

If two of these loops do fit precisely, then there must obviously be one position in the middle of the 'rope' where there is no movement. With three fits, there'll be two positions; with four, three, etc.

This is the nittious grittious. If you rest a finger lightly on the string on the spot where this dead area falls and then pluck, what happens? The whole string can't vibrate as it would normally do because you're inhibiting its movement, and you haven't pressed hard enough to fret it. Instead, the string is forced into vibrating in two halves, either side of your finger, so generating the first harmonic — a note an octave higher than the open string.

This is the skill of harmonics — finding these dead spots, or nodes as they're known, and twanging them.

Where Are They?

The three most obvious positions are those already mentioned — above the 12th fret (octave); above the 7th and 19th frets (octave-and-a-fifth); above the 5th, 12th and 17th frets... right?

Wrong.

Thought you knew it, didn't you.

The first two, loudest examples can confuse people into thinking that harmonics are connected with fret positions when, in fact, it's purely string length. The frets can be useful aids to memory, but that's all.

Just because the octave-and-a-fifth falls at both B positions on the E string, that doesn't mean the two-octave versions will fall at both A positions.

Measure the distance from the nut to the 5th fret (usually about 160mm, depending on scale) then mark the same distance from the 12th fret, along the string, towards the bridge, and that's where you'll find the remaining two-octave harmonic. On a three pickup Strat it generally falls just over or in front of the neck pickup. You won't get the two octave harmonic at the 12th fret — at least you won't be able to hear it — because the one octave, first harmonic is much stronger.

There are plenty of harmonics between the end of the fretboard and the bridge. They're just as easy to play, but harder to locate in a rush as there are no frets to act as maps. Again, don't think that just because the frets would be crammed close together at this point (if they existed), then so would be the harmonics. Their spacing stays even throughout the string length.

The next section deals with how to sound your harmonics clean and loud, but before we park the mental process in that garage, are there any other places to go node hunting?

There are guitarists who will tell you that over every fret hovers a harmonic — some even live between frets. While theoretically, this may be true, the chances of getting enough volume to do something useful are not boundless. Success will also depend on your guitar, the strings, direction of the wind (etc).

However, you might reasonably expect to find something around the 4th/9th/16th frets (and equivalent spaces beyond) and the 2nd and 3rd frets. Both the latter are different in pitch and ought to have equivalents falling at fret positions further down the neck. But, the closer you get to the 12th fret, the more you'll find other, louder harmonics clamouring for attention on the same frets. They win. Incidentally, with that harmonic on the third fret, it might help to drift off the fret, say a third of the way towards the 4th.

How To Get Them

There are artificial aids to sounding harmonics, at least on an electric. New strings, tail pickup selected, a treble boost at the amp, a chorus unit and a compressor will all help lift them in volume and strengthen their presence.

Physically there are also things you can do. Try to touch the string with the smallest area of finger you can manage — especially important for the advance harmonics. The more loops packed into the rope, the smaller the area the nodes take up and the greater the chance of a big, fat digit producing a flesh overspill and damping the vibrations either side of the dead spot. This, by the way, is why harmonics are frequently easier to get on basses. The increased string length produces wider nodes.

I've seen some guitarists go to the extreme of harmonically 'fretting' with a fingernail, or the edge of a plectrum, but in most cases, swapping to your little finger should be enough.

Don't pluck the string too hard, that will only encourage it to go back to its fundamental. Lightly does it.

In Plural

No law forces you to play only one harmonic at a time. Two and three are easy, and with careful finger manipulation you can go further, though it's more difficult to shape your fingers to a chord precisely above the frets than it is to slap them down on the board in roughly the right location.

Play all six strings in a big line across one fret if you have to, but don't do it all the time. Why? Because everyone's done it, it's very ancient and hackneyed, and we allow only the most creative musicians to place regular orders with OTT.

Likewise, experiment with normally fretted chords that have a harmonic thrown in (try it on the top E to begin with). Your little finger will need to stray hither and yon to achieve this, and it's worth the effort for the nuances it can add to otherwise ordinary chords.

Stopped Harmonics

We've paraded through this technique before in previous One Twos, but it bears repeating.

No matter how hard you hunt, there are only a limited number of harmonics on each string, and the selection of pitches is far from infinite. If harmonics are a product of string length then one way to find a whole new set of notes is by shortening the string.

So, we commence by fretting a string with the left hand, but realise that we now have to touch the harmonic node and pluck the string, all with the right hand.

The common trick is to use the tip of the index finger of your right hand to rest on the string, doing the same job that the little finger of your left hand used to do. Try this exercise in front of you now. Keep it stretched out straight ahead and place it on a flat surface. Without changing its position, scratch the surface with the nail of your thumb. It may help if you curl your second and third fingers up out of the way.

This is the action you need — your thumbnail plucks the string while your index finger points along its length towards the headstock, and your whole hand moves to position it over the proper fret.

You'll have to recalculate the harmonic positions depending on where you've fretted the string with your left hand. It's one of the most awkward and crampinducing skills you'll have to master, but desirable for the fund of additional 'plings' awaiting your call.

(Two alternative ploys are as follows: (1) Use the index finger to 'fret' as before, but pluck the string with the fingernail of your third finger. It's harder, and you'll have to point downwards across the strings instead of along them, but it leaves the thumb free to sound bass notes as well as the harmonic. (2) Crook the thumb of your right hand and apply the edge of that to touch the strings, then use the first fingernail to pluck them. This second option is perhaps better on basses where players are already used to positioning their thumbs over the strings for slapping, and the wider nodes don't get so fussy about the acres of flesh.)

Bend Beneath It

One glorious advantage to harmonics is that you don't have to keep your hands on the guitar. Take your mitts away and the notes will carry on ringing quite happily. This leaves the absent digits room to play around.

Your first visit should be to the length of string between the nut and the machine head. Pushing down on this will bend the pitch of the harmonic upwards. (For variety use the stopped harmonic technique while this part of the string is depressed, then release it so the harmonic bends downwards.)

Certain guitars may have a stretch of string between the saddle and stop bar/tailpiece. Pressure here has the same effect.

If you've played a stopped harmonic, then bending the note with your left hand where you've fretted it can be intriguing, and one popular country favourite is to pluck the string normally as you bend upwards, then 'stop' a harmonic with your right hand as you release it. The same harmonic interruption can be used in lots of ways like sliding up a string and ending in a harmonic, but for most of these you'll need to be nifty with the right mitt. 'Course, if you've got a trem, the world is your constantly mobile standing wave.

Squeaky Clean

A practice impossible to demonstrate in pictures, and almost impossible to describe in words, but much beloved of chaps with long curly black hair and a bus full of Marshalls.

Decide on a block of frets that you enjoy soloing around — 5th to 7th or 12th to 14th for example. With the strings fretted in that area, search around with your right hand in the area above the pickups until you find the loudest harmonics (remember the first lesson — it's the length that counts).

Now, go back to soloing, but instead of using the plectrum to pluck the string, rub its edge sharply across the string 'tweaking' it, if you like. But do it precisely where you found the harmonics beforehand. With practice you get a harmonic halfway-house — a sound that's part fundamental, part harmonic.

It can help if you bend the string as you're striking it (explanations vary, but I reckon it might have something to do with the corresponding increase in speed with which the plectrum scratches across the string, plus the extra tension).

You may have to move your right hand back and forth to hit the spot as your left hand riffs away, but you'd be surprised how much you can get away with, once you've perfected the tweak.

Hitting Out

One final approach which, again, you may have spotted in previous One Twos, but is worth bringing under the roof.

Form a chord with your left hand (a barred E is an easy start), find its equivalent position beyond the 12th fret and, in these locations, strike all the strings sharply with the edge of your thumb against the fretboard, and snatch it quickly away.

With luck and rehearsal you'll get many of the notes of the chord reproduced as harmonics. That barre E is neat because the shape of your thumb follows much the same profile as the A, D and G strings (two together under the knuckle and one further down under the nail).

What's happening here, ironically, is exactly the opposite of previous examples. The frets themselves are momentarily stopping the strings at their harmonic positions. The hammering action is sounding them. As a final frippery, slap the tip of your index finger against the bottom E string at a new fret position and keep it there to supply you with a new bass note.

Hop to it, and don't ring us.