Guitar Theory From First Principles, Part 3

In articles 1 and 2 we started learning about the fretboard, the key (including the major scale, intervals, triads, chord scales and chord progressions) and the CAGED chord system. This month we will be pursuing our lead guitar development by reducing the major scale to modes (or inversions) in the name of improvisation (the good stuff!); and sharpening our rhythm attack by exploiting the CAGED system further.

There has been much said and written about modes in the guitar media. Legendary guitarists like Brian May and Joe Satriani often refer to these enigmatic patterns with respect to their lead guitar methodology. Unfortunately the strange Greek names and perplexing explanations often create confusion. For years I struggled to unravel modal theory with its strange terminology. Eventually I prevailed, but only once I understood the notes of the patterns properly. Once you study the notes and their location on the fretboard then the theory will become clear. In addition, it is only when you know a pattern well enough to eliminate the focus on technique or fingering that you can really begin to listen.

Dig out your fretboard (article1) and carve up a two octave C major scale using the "T T st T T T st" formula (article 2) i.e. CDEFGABCDEFGABC.


Now play from D to D within the C scale i.e. DEFGABCD in any position and memorize the pattern.


This is called the D mode or D inversion of the C scale. It has the same notes as the C major scale. It is also known as the D Dorian Mode (the inversion's ancient Greek name. Music theory is also littered with Latin and Italian so keep a glossary handy.)

The trick to getting the modes working for you in terms of improvisation is to ensure that the chord progression you jam over 'turns around' on the root chord of the mode. Dm is the root chord of D Dorian because the 1st, 3rd and 5th notes of the mode are DFA, or a D minor triad (article 2). Grab your looper pedal or portastudio and record the following example of a Dorian chord progression i.e. a progression that starts and repeats (turnaround) from the Dm chord in the key of C major e.g. Dm G C Bmv5 (or ii - V - I - vii) and improvise with the D Dorian mode over it. To begin with ensure that you mix and match every note, listening to how each note and phrase works with the chords below. The only rules to improvisation are, if it sounds good it is good and be prepared to stand by your ear. If you are struggling to get started, try making it your goal to produce some sort of memorable melody. Then use your techniques to embellish the melody with taste and expression. Listen to the way legendary improvisers like Jimi Hendrix or violin virtuoso Stefan Grapelli decorated their lines to get an idea how it is done.

Try experimenting with different Dm turnarounds using the remaining members of the C major chord scale i.e. Cmaj Dm Em Fmaj Gmaj Am Bmv5 (article 2). Also explore different rhythm styles i.e. rock, jazz, classical, folk, funk etc because it is the chord backing which determines the vibe of the melody. After a few weeks you should begin to get a grip of the Dorian sound but it is worth remembering that when it comes to improvisation, 'beauty is in the ear of the beholder'. In the next article we will learn how to extend chords into 6ths, 7ths, 9ths etc which will give you further control over your backings and give you new improvisational insights.

There are 7 possible inversions of the C scale so once you get D Dorian down it is time to develop the other modes using the same approach. The remaining inversions of the C major scale to improvise with are: C to C, E to E, F to F, G to G, A to A, B to B; and each will require separate sessions, with bespoke chord turnarounds. Once you get familiar with the basics, it will be worthwhile researching the modes in greater detail. Ensure you check out the articles with references to modes in your GW back issues and test your knowledge.

Let's turn our attention to rhythm guitar and the CAGED system. In articles 2 and 3 you learned to build your own basic triad chords from scratch and by moving the open CAGED shapes around the board. If you now flatten the 3rds of each triad that make up the CAGED major chords you will create the CAGED minors. Then if you flatten the 5ths of each CAGED minors you will get the CAGED diminished chords. Build them all and slide them around as bars (article 2).

Next: We will pursue improvisation and composition by learning how to build scales such as the Natural Minor, Spanish, Blues and Japanese Pentatonic scales from the major scale. The saga of the CAGED system also continues with 7th, 9th, 11th and 13th extensions.

Guy Pople is a music, education and multimedia specialist based in the UK`s North-West. He plays guitars, studies theory and runs St Annes Music in Lytham St. Annes, a one-stop shop for musicians on the Fylde coast of Lancashire. St Annes Music offers professional instruments, recording, tuition and accessories.

His live band Nomad is currently building up their original music. You can catch him
on Virtual Strangers.

Guy Pople

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