The use of twin guitar harmonies - two simultaneous guitar lines playing different pitches at the same time - is very common in metal guitar. This can be done either live with two guitarists, or in the studio via multi-tracking. Live, when you lock in with your second guitarist and perform a soaring dual harmony line, it can be an exhilarating feeling!


By far the most common way used to harmonize solos and riffs is to use diatonic major and minor thirds. Let me explain what this means. Harmonizing is all about having a good knowledge of intervals. An interval is the distance between two notes. One type of interval is called a minor third - one and a half tones (or three frets on the guitar) = between the original note and the other. A major third is two tones (four frets) apart. When major and minor thirds are combined, you get that classic ‘Iron Maiden’ style of guitar harmonization. But how do you know whether to use a major or a minor third?

The key word is diatonic. This basically means staying within the scale. Exercise 1 simply harmonizes the first five notes of an E Natural minor scale. The first part of the exercise is the original line. To harmonize it in diatonic maj/min thirds you count up three notes and then play the lick using the same melodic movement. Most importantly, you stay within the scale. By staying within the scale, it dictates whether the intervals will be a major or a minor third. So here, when both parts are played at the same time, the intervals are: min 3rd, min 3rd, maj 3rd, min 3rd, min 3rd.  

Hear Exercise 1


To illustrate this, I’ve written a short solo in E Natural minor using a Im-III-Im-Vm chord progression. It begins with a melodic passage before moving into an ascending, alternate-picked ‘shred’ run.

Hear Exercise 2


To harmonize our original solo in diatonic thirds, you play the line using the same rhythmic/melodic contour, only three scale tones higher = always staying within the scale. A good knowledge of scale finger patterns across the neck helps. Note here that the bends are only a half-step (to keep it diatonic). You also want to keep the vibrato of both parts the same too.

Hear Exercise 3


Although using maj/min thirds is certainly the most prevalent way of harmonizing in metal, you can also use other intervals, such as diatonic fifths. You stay within the scale, but you keep everything five notes apart.

Hear Exercise 4


You could also harmonize the original line using diatonic sixths. This would be six notes of the scale above the original solo, or more commonly, it can be viewed as a third below the primary line as is the case here.

Hear Exercise 5


Although not notated, Exercise 6 involves putting Exercises two, three and four together to create a three-part harmony. Unless you have three guitarists in your band, you’ll have to do this in the studio. What you get though is a harmonized line forming a basic three note triad.

Hear Exercise 6


Thirds and sixths can also be combined along with the original guitar line. Be aware that you can’t use fifths and sixths at the same time, since both intervals are too close together and will clash.

Hear Exercise 7

Try these exercises out by playing them with a friend, or by recording them together. These are just a few of the more common ways of using double (or triple) guitar harmonies. Next issue I’ll show you some more.