Welcome back to this overview of intervals in guitar playing! In part one, we looked at thirds, sixths and tenths. In this follow up article, we will be taking a brief look at fourths and fifths. Both of these intervals can be used more ambiguously, as they remain the same in the context of a major or minor chord (when sticking to notes in diatonic scale, at least – more on that later). Because of this fact, they can utilized in slightly different ways to the tones they sit alongside in common scales. Let’s take a look…

Fourths

Fretting the two highest strings together at the same fret creates this classic double stop, which can be heard all over rock’n’roll, but famously in the intro and solo for Chuck Berry’s Jonny B. Goode. Berry developed this style so he could recreate horn lines, as his live band was a smaller ensemble than many bands of the time (which would typically have more than one sax, trumpet, trombone, among other brass instruments). Every rock guitarist that followed has used phrases first made famous by Berry, from Angus Young to George Harrison. It is also a useful interval for slide guitar playing as it can be used over major and minor chords alike (you can see an example of me playing 4ths with a slide on this cover video of a well-known song).

In jazz, Wes Montgomery pioneered the use of stacked fourths, creating chord-based solos using 4th intervals on top of each other (for example, one chord would sound, low to high, as A, D, G, C), and the shape would move in line with the melody. George Benson kept up this tradition, but would also regularly employ diads (two notes played together) of 4ths in his lightning-fast solos.

Fifths

A fifth is an inversion of a fourth, and vice versa. Here, the strict definition can become blurred – think of the intro to the Deep Purple song Smoke On The Water and you’ll hear diads playing the entire riff in what sound like fourths (eg, the first pair of notes is a D, then a G on top). However, since the melody is following the G minor pentatonic scale (as the song is in the key of G minor), I’d argue that this riff is an inverted fifth (D being the perfect fifth of G), as the melody note is higher than the harmony note.

In rhythm guitar, a root and fifth creates the classic power chord heard in most varieties of rock music. Alternating the fifth with a sixth, and moving back and forth between the two, gives the famous (almost cliché) rocking riff used by artists from Chuck Berry to Status Quo and beyond.

Variations on ‘perfect’

The intervals we have discussed above – using the fourth and fifth notes in a diatonic scale, create what is known as perfect fourth / fifth. However, as with any note, we can raise or lower it’s pitch by a semitone for a new musical sound. Flat fourths & fifths are both referred to as diminished (and of course be found in diminished chords and scales). Raised ones are called augmented. As a fourth and fifth are only a tone apart, a diminished fifth is exactly the same thing as an augmented fourth – just in case you were confused!

Apart from being the famous Devil’s chord (famously used on the Black Sabbath song Black Sabbath), this interval often occurs in Blues-based music. The Pentatonic Blues Scale is based on intervals of R, b3, 4, #4, (or b5), and b7. Likewise, in dominant seventh chords (for example, C7), the natural interval between the chord’s major third (E) and flat seventh (Bb) is a diminished fifth/augmented fourth. Highlighting these notes over these chords creates a wonderful effect without having to overthink your playing too much!

Finally…

There are a few intervals we haven’t covered in these two articles. Off the top of my head, these would be seconds, sevenths, octaves and extended intervals used in jazz chords and arpeggios, such as ninths, elevenths and thirteenths. I plan to look at octave-based playing in a future article, because it is a staple of my own guitar heroes, such as the great Wes Montgomery. However, if you’d like me to look into some of the other intervals (such as sevenths, which is a really useful colour tone in jazz), do let me know!