Learning to Play Better Guitar – Substitution Principles – For the Advanced Guitarist
First and foremost, this article is not for the beginning guitarist. For those who are in the early stages of learning how to play the guitar, please refer to some of my earlier articles. This particular article is geared more in the direction of the advanced professional guitarist. It presumes a very strong background in music theory and a few solid years of guitar under the belt.
Substituting guitar chords and guitar scales can add a tremendous amount of interest to any melodic structure or harmonic structure. Guitar solos and chord progressions take on a whole new life when substitution principles are utilized. Substitution principles add tonal interest and surprise for the listening audience.
Take, for example, a simple ii,V,I progression in the key of two sharps. For the sake of interest, let’s extend each chord to it’s diatonic 7th. Hence, ii mi7, V7, IMa7. This translates to an Emi7(ii mi7)-A7 (V7)-DMa7(IMa7) progression in the key of two sharps. By the way, and as a reminder, a ii, V, I progression is a very strong chord progression for ear training. The ii chord (minor) is an excellent departure away from the tonal center (major), whereas the V chord (dominant in function) is the strongest chord leading back to the established tonal center (major). The ii, V, I progression is very clinical in application. However, it’s a great chord progression to practice and experiment with.
Without meaning to state the obvious, did you notice that a ii, V, I progression immediately infers a diatonic chord progression? No alterations were referenced. Chord extensions yes, but alterations, no. Therefore, we know that we’re dealing with a diatonic tonality. This is good news for purposes of improvisation and easily identifying possible substitution principles.
We all know that there are several different ways to improvise, substitute, and analyze any particular progression. However, when harmonizing a solo, substituting one scale for another, or employing chord substitutions, our sense and knowledge of tonality needs to be accurate. This is why it’s always good to view things in the diatonic sense whenever possible. Everything just gets easier when we think in terms of diatonic relationships. In short, once we understand the diatonic relationships, the chromatic issues will stand out like a sore thumb and can easily be dealt with. Once again, and as I’m sure that you all know, tonal identification at every step, is essential to an accurate musical translation.
The ii, V, I progression in the key of two sharps should immediately conjure up an Ionian tonality as the all-important tonal center (remember to think in diatonic terms). Once in the spirit of Ionian, all substitution principles are very easy to employ. As an advanced guitarist, these principles will offer your listener several interesting musical alternatives. This is the fun part of musicianship, regardless of instrument.
As you know, ii is a great substitute for IV, and the reverse also holds true. In other words IV will substitute for ii. The Dorian and Lydian substitution principles add tremendous color to your solo approach or chord application. Let’s examine the Dorian (ii) and Lydian (IV) as pure scales and scale tones. In fact, let’s harmonize each scale with it’s substitution partner and examine the musical effect that each one has on the other.
For the sake of simplicity in explanation, let’s examine Dorian and Lydian in the key of no sharps and no flats. The Dorian yields the following notes: D-E-F-G-A-B-C-D. Lydian yields F-G-A-B-C-D-E-F. By harmonizing Lydian with Dorian we arrive at the following: D over F, E over G, F over A, G over B, A over C, B over D, C over E, and D over F. I won’t waste your time by explaining the interval relationships between each combination of harmonized notes. However, as I’m sure the advanced guitarist will know, all of these relationships are diatonic. Thus, we end up with a wonderful harmonization of two completely different, yet diatonic, scales. This results in a perfectly harmonized solo line (if you so choose to create a harmonized solo line) and a bonus for your listener.
By superimposing Lydian over Dorian, we create an entirely different sound (look at the interval relationship) using the same notes: F over D, G over E, A over F, B over G, C over A, D over B, E over C, and F over D. Once again, we arrive at a harmonization with the potential to add great interest to your guitar solo, vocal line, string line, keyboard line, and so on.
The ii-IV substitution principle, as described above, is also available for chord substitution. For example, the ii minor chord will substitute for the IV major chord. The reverse also holds true; the IV major chord will substitute for the ii minor chord.
Let’s assume a IV, V, vi progression in the key of no sharps and no flats. Look at the ii minor chord as eventually substituting for the IV major chord. Also try the reverse (IV major chord substituting for the ii minor chord). Place the ii minor chord on top of the IV major chord (poly-chord effect). Place the IV major chord over the ii minor chord. As you know, the possibilities are endless here.
Another great substitution principle is the V-vii min 7b5 (Mixolydian and Locrian). As pure scale tones, these two modes, when harmonized, offer a very unique sound (unexpected). Once again, and in the spirit of Ionian, let’s take a quick look at the harmonization aspects of Mixolydian and Locrian (for both chord and scale substitution).
The Mixolydian yields G-A-B-C-D-E-F-G (key of no sharps, no flats). Locrian yields B-C-D-E-F-G-A-B. By superimposing the Mixolydian scale over the Locrian scale we arrive at G over B, A over C, B over D, C over E, D over F, E over G, F over A, and G over B. Look at the intervals ( all diatonic 3rds) (diatonic 6ths when inverted). As a side-bar issue, it’s really important to understand chord quality, interval relationships and inversions of intervals. I say this just-in-case you’re not an advanced guitarist, and reading this article against my strongest advice. Remember, this article is intended for the advanced guitarist, not for the beginning or intermediate guitarist. Why? Because I’m cutting-to-the-chase with most of the theory here. The advanced guitarist understands the concepts in this article; many of the less experienced players might not.
Now, let’s superimpose the Locrian scale over the Mixolydian scale. The resulting scale tone combinations are: B over G, C over A, D over B, E over C, F over D, G over E, A over F, and B over G. Look at the intervals again (all diatonic 6ths). This is a very unique sound. Try it next time you need to harmonize a V-Mixolydian scale or a vii-Locrian scale. The V substitutes for the vii and the vii substitutes for the V. This also occurs with the V chord and the vii chord. Each one can substitute for the other. There are many times that instead of voicing a G7 chord (key of no sharps, no flats) in a progression, I’ll opt to substitute a Bmi7b5 chord in the place of the G7 chord. It sounds great! At the very least, I’ll run a Locrian scale over the Mixolydian chord (or the reverse). The point here, especially for the advanced guitarist, is to always strive to utilize substitution principles for added musical color. By the way, don’t forget the poly-chord effect by stacking the two chords described herein.
In future articles, I’ll address the more difficult aspects regarding harmonization and substitution principles. As we all know, diatonic relationships are simple to understand. Chromatic relationships are more involved theoretically, and demand an intense analysis and understanding between the two concepts (diatonic vs. chromatic).
Learning to play better guitar is a choice that we all must make for ourselves. It’s a personal decision. Remember, however, that no matter how advanced and professional we are as players, there’s always room for more experience and advancement. My advice to everyone, at every level, is to keep on learning. This will lead to progression. Progression is our friend.
©2009 Michael E. Fletcher. All Rights Reserved Worldwide.
