By: Will Wallner
In this lesson I want to give an introduction to the topic of intervals and begin by focusing on a particular interval known as a ‘third.’ Let me begin by explaining what an interval is. An interval is the difference in pitch between any two notes, and is used to measure the difference between those two notes.
For example, if you play any two different notes on the guitar they are separated by a specific interval. For a beginner, it’s important to know that they are a very useful tool for any musician. I’ve found that they can give you creative ideas when it comes to writing riffs and when playing leads. There are many intervals, but for this lesson we are focusing on a relatively short interval known as a third.
Let’s begin by learning what a third is. To do this we need to pick any diatonic scale, and as I’m a rock guitar player, I’m going to choose A Natural Minor, but you could use any other diatonic for this exercise. You want to play the scale over two octaves and number the notes of the scale 1 to 7, which looks like Figure 1.
Notice how when you get back to the root of the second octave the numbers begin at 1 again.
Now you want to play the scale in the following pattern: 1 – 3, 2 – 4, 3 – 5, 4 – 6, 5 – 7, 6 – 1, 7 – 2, 1 – 3, etc. This is Figure 2.
Each set of notes is actually a third, and if you look closely, you’ll see that when you play the scale like this, there is always either a 3 or 4 semitone difference between each pair. For 3 semitones we call this a minor third, and for 4 semitones we call this a major third. The reason for that is very simple, if you look at our A Minor Scale, the first third is a minor third and for a major scale the first third is major third.
When you play a diatonic scale in thirds like this, it gives the scale a different sound because we are focusing on the thirds. When you play each third as two separate notes, one after another, it is known as a melodic interval. If you play the two notes at the same time, it is known as a harmonic interval. Figure 3 shows A Minor played as harmonic intervals.
I often advise playing around with harmonic thirds to write riffs. They can be a nice change to playing just power chords (which by the way are also just another type of interval). Ritchie Blackmore uses a lot of thirds in his riffs – check out the Rainbow songs “Stone Cold” and “Stranded” for examples of this approach.
Now you have an introduction to thirds I want to give you some musical ideas. Figure 4 is one of my own riffs based on harmonic thirds in E Minor.
Figure 5 is a descending lick played over three octaves in A Minor.
Use thirds to increase your lead lick vocabulary and as an option to use something other than power chords when writing riffs.
About Will Wallner
Will Wallner is hard rock guitarist from England currently living in Los Angeles. At age 24 he has worked with many influential musicians from rock and metal including Carmine Appice, Vinny Appice, Rudy Sarzo, Tony Franklin, Derek Sherinian, Brian Tichy, Jimmy Bain, Tony Carey, Bob Kulick and many more. His debut album features these musicians providing an all-star backing to Will Wallner’s original compositions. For more information please visit Will Wallner’s homepage.