In The Woodshed

Whether you’re on the light side or the dark side of the 4ths, the tritone interval is one of the most fascinating of all. With Charlie Griffiths.

- Charlie Griffiths

The interval we’ll be exploring this month has at least two names; the b5 or the #11. You could also call it the #4 or the tritone. Whatever you call it, the point is it can be an extremely evocative and powerful interval and can have radically different effects depending on the harmonic context. For example, the tritone intro to Purple Haze is a little scary and dangerous sounding, but the intro to the Simpsons is playful and quirky. In common harmonic settings like pop or rock songs, playing the b5 for an extended time will sound grating, so usually it’s more suitable as a passing note; great for a moment of tension, but not to be lingered upon.

In the following examples, we will use the interval as the focal point in a few different harmonic settings, from metal to jazz-fusion. Generally speaking, if used in a minor tonality we call it a b5 where it sounds dark, but if used in a major tonality, we call it a #11 and it sounds more magical.

Our first example is based on the Blues scale (1-2-b3-4-b5-5-b7). Usually, we think of the Blues scale as something we use for jamming over pretty much any chord. In this scenario, the b5 interval works best as a passing note, which we tend not to stay on for too long as the dissonance can sound a little too dark. This Tony Iommi style riff, however, makes full use of that dark dissonance and fully embraces the ‘Diabolus in Musica’. In tracks like Black Sabbath, the b5 interval immediately evokes a foreboding atmosphere which is a lot of fun to explore.