Guitar Intervals – The Music Theory Building Blocks

In my earlier article on guitar intervals I gave a quick overview of what they are and why we refer to them all the time in musical circles. The basic principle is very simple – at their heart, intervals simply express how far apart two notes are. This distance is measured in terms of tones and semitones (often also called whole and half steps).

Let’s take a look at some of the intervals that you’re likely to come across when playing the guitar.

Major Second

The interval in this case is simply the gap between the first and the second note of the major scale. So, for example, in the key of C, the major second interval is the gap between C and D.

If you play the major second a whole octave higher, this will give you the major 9th interval.

Major Third

The major 3rd is the interval from the 1st to the 3rd note of the major scale. So, using the key of C as the example again, this would be the interval between C and E.

The major third interval is very important because it defines the tonality of the chord you’re playing on the guitar. Whenever you play a chord containing the major third interval (from the root) it will always be a kind of major chord.

Minor Third

Lowering the major third by a semitone (or half step) turns it into a minor third. The minor third defines the tonality of the chord as a minor chord.

Perfect Fourth

This is – you guessed it – the interval from the first note in the major scale to the fourth note. Are you starting to notice a pattern here? I certainly hope so! Once again, in the key of C, this would be the distance from C to F. The perfect fourth gives quite a strong harmony when the two notes are played together, but fourths sound weak when compared to the next on the list…fifths.

The Perfect Fifth

This is the Big Daddy of all the intervals on guitar. It will come as no surprise by now that this interval is the gap between the first and the fifth notes in the major scale. I.e. from C to G in the key of C.

The harmony between the two notes of this interval is so strong that you can almost feel the resonance in your body when you play it. It is a very pleasing sound to hear and is very popular with heavy metal and rock guitarists who need a very strong harmony in order for their playing not to sound “muddy” through the heavy distortion effects that they employ. Perfect fifths keep things nice and crisp.

If you lower the fifth interval by half a step is turns into a diminished (or flattened) fifth.

Conversely, if you raise the perfect 5th by a semitone, it becomes an augmented (or sharpened) fifth.

These half steps may seem like trifling details to the uninitiated but they can make a profound difference to the music you’re playing.

Major Sixth

At the risk of becoming monotonous, this interval is the gap between – surprise, surprise – the first and sixth notes of the major scale (C to A in the key of C).

You can get the major sixth in both major and minor sixth chords. And in the same way as you can play the octave above the second interval to get a ninth chord, here you can play the octave above the sixth to get a 13th chord.

Major Seventh

Finally, the major seventh is the interval from the first to the seventh note on the major scale (no surprises there). The example for the key of C would be from C to B.

You’ll find the major seventh interval in major 7th chords. These types of chord are used quite a lot in blues music and Jimmy Page used them a lot during his Led Zeppelin days to great effect, too. Seventh chords sound great when played with chromatic variation (moving up and down by half a step) and add extra colour to your music.

Lowering the major seventh by half a step turns it into a minor seventh. This interval can be found in minor seventh and dominant seventh chords.

There is of course much more to intervals and the chords that they are used in than I have cover here, but I will return to them in the future to offer more insights and explain further.

In the meantime, you should practice playing them and see whether you can teach yourself to recognise each interval just from hearing it played to you. You can do this by identifying a song that you’re familiar with that contains the interval you want to learn. This makes it easier to identify the interval when you hear it because it is just part of the melody to one of your favourite songs.

An even better way to practice and train your ear to recognise different intervals is by using ear trainer software such as Pitch Master Pro – Ear Training Software. Click on the link to find out more!