Modes - what are they?

The modal system can seem confusing, complex, or just plain pointless!

I am therefore starting with a simple example, one bar of G, followed by a bar of F and C:

Referring to my tutorial 'Which chords to use?', it could be said that this progression is in the key of C major I.E. These chords can all be derived from the C major scale and ,when harmonising all major scales, it is only from the C major scale that all three of these chords are established.

Click here for all harmonised major scales, if you wish to check for yourself.

However, by improvising over the track (or even simply looking at it) we can establish that the 'tonal centre' is G - I.E. the progression 'rests' on the chord of G major and a G note 'sounds strongest' throughout the progression.

Many players may regard this piece as being in the key of G major for this reason.

However, this cannot be so - because if we play the notes of the G major scale over the progression, slowly and listening carefully, we can hear that it doesn't quite fit.

The notes of G major are G, A, B, C, D, E, F#, G.

It is the seventh note of F# that doesn't fit over the F chord.

So it is the notes of the C major scale that fit - C, D, E, F, G, A, B, C - but we need to take into account that the tonal centre of the progression is G.

What we therefore end up with is G, A, B, C, D, E, F, G - the G mixolydian mode.

This demonstrates the practicality and simplicity of the modal system.

The above process involved deriving a G scale from the C major scale, and this is what the modal system does. It takes each note of a major scale and regards that note as the tonal centre. Here is what you get, using the C  major scale:

The following video explains what modes are, why you might need to use them, where they are, and how to identify and remember the box positions for each. I strongly recommend you watch it with your guitar in hand, so that you can relate the content to your understanding of your instrument in order to create lasting knowledge rather than a 'vague idea' of how this system works.