MUSICAL MODES 16
Mediant substitution (Part 3)
The musical modes offer a great way of developing your harmonic vocabulary, and mediant substitution is a simple but powerful technique for making all your modal chord sequences sound more sophisticated.
The basics of mediant substitution are explained in
Module 14 of this Musicarta Musical Modes series of free online piano lessons.
This Module applies the mediant substitution technique to the chords introduced in Module 6 of the series, which you might need to revise.
You will benefit most by working through the whole Musicarta Musical Modes series in sequence. If you have not done so, link through here to the Musical Modes series covering page to get started.
Inversions of i, bVII and bVI
This Module applies the mediant substitution technique to the chord sequence in Module Six – chords i, bVII and bVI (One minor, Flat Seven and Flat Six).
In A Aeolian minor, these chords are A minor (i), G (bVII) and F (bVI).
Run through the three sets of inversions of the three chords:
Simply as a way of getting started, you play the three second inversions first, then the first inversions, then the root positions.
Because we’re playing in all-white-key A Aeolian minor, you can safely count keys from the name-note (root, arrowed/circled in the table) to find the inversions::
Find the inversions by counting the play one, miss one notes off according to the table (as suggested), by using the Musicarta Visual Chord Generator, playing by ear from the audio clip or simply reading the music.
You probably need to drill (practice) the inversions. You can make it sound more musical by using the G chord from the next set of inversions to transition between positions (circled in the following MS example), and finishing it off neatly.
Note: Practising cycling through the three sets of inversions in a chord sequence like this is the quickest way to put the chords you want under your fingertips.
Add a beat and a broken chord pattern, and you’re learning something usable as you practice. The BMT (bottom, middle, top) pattern used for the first six bars is:
(The colon : indicates that the bar is split equally between the two chords.)
The second time the chord sequence is played, the first note of the second (and fourth and sixth) bar is dragged forward (anticipated). Listen carefully to the audio clip until you can hear it, and imitate it – once you can play the ‘straight’ version.
Creating a riff with mediant substitution chords
Mediant substitution is a way of making your chords sound richer by lowering the root of the existing three-note chords (triads) to create new seventh chords.
If we shift the bass line of the last music sample down a third (except for the last two chords), we get this:
This audio demonstration of mediant substitution plays through the substituted seventh chords twice, then adds broken chord and rhythmic variation to turn the exercise into a usable riff.
Here is the written out music for the riff performance:
The BMT analysis (bottom, middle, top, plus C for chord) refers the ‘looks like’ triads played as the upper part of the seventh chords. Refer to the keyboards diagrams above if necessary to remind yourself what they are.
Students of solo keyboard style will find close study of the fingering given here most rewarding. There are very few alternatives if you want to play both chords and melody in your right hand – as a solo performer must. Use solo pieces like this as exercises to make your hand learn the necessary skills and conform to the requirements of the style.
Writing mediant substitution chords as seventh chords
As explained in (the previous two modules), we can’t normally write down seventh chords as slash chords. The proper chord names for these chords are:
You will find it easier understanding the seventh chords if you remind yourself that:
A MAJOR SEVENTH CHORD looks like
its root plus a minor chord built on the note a major third higher
A MINOR SEVENTH CHORD looks like
its root plus a major chord built on the note a minor third higher
Mixed original and mediant substitution chords
The audio riff above uses all the possible mediant substitution seventh chords. The ear can find this overwhelming. Here are some more riffs which mix original chords and mediant substitution seventh chords.
The right hand still plays only A minor, G and F triads. The bass (left hand) is either dropped a third to create mediant substitution seventh chords or not. Seventh chords are written ‘properly’, not as slash chords. Work out from the keyboards above which ‘looks like’ triad to play.
1. The right hand chords are shown stems-down. Find these first, as in the audio file.
2. The stems-up notes are the melody, which you will add once you know the chords. You have to finger the chords so that you don’t run out of fingers for the melody. Drop the rhythm while you drill the melody.
3. Last, add the rhythm. You don’t have to play exactly what’s in the audio clip – any jazzed-up version will do.
The audio plays the chords straight (with the ‘repeat three times’), then with syncopated right hand chords and straight bass, then with the bass joining in the syncopation. Sing or clap along with the syncopated part to get the rhythm through to your fingers.
The right hand is still playing just A minor, G and F triads. Look at the shape of them – they are all first inversion P M P M M P triads (triangle symbol). Exactly half of them are mediant substitution seventh chords.
This riff goes well with the previous riff, and would work as a backing for a solo or vocal.
Create your own ‘mixed’ type riff
Revisit this Module Six riff and see how much mediant substitution (dropping the bass a third) you think it needs.
Here are the chords and the full riff audio.:
Revisit the relevant part of Module Six to build up the rhythmic/broken chord texture if necessary.
Here are the chords with the entire bass line dropped a third (all mediant substitution):
Here’s how to proceed:
- Play the Module Six riff right hand texture over the new bass line to hear what it sounds like.
- Play the original again.
- Decide where you would drop the bass to get the mediant substitution seventh chords and where you would leave it as it is. Remember that you can repeat the riff and have different substitutions every time.
- Write down the chord sequence of the mix you decide is best.
- Try joining the result up with the two riffs in this module to make an extended instrumental piece.
This is the end of Module 16 of the Musicarta
Musical Modes series of free online piano lessons.
Every time you apply the mediant substitution process to a set of chords you deepen your understanding of how harmony and popular music work. More and more chords will seem to appear under your fingertips.
In the next module, we apply mediant substitution to the D minor, C and B flat and E minor, D and C groups of chords from Module Seven.
In the meantime, make sure you stay up to date with all the free online piano lessons on offer at Musicarta by visiting the Musicarta home page regularly. (Most Musicarta students study a couple of lesson series in tandem, for variety...)
Use the ‘Sounds’ page, Musicarta’s audio table of contents, to help you find something you like. Work through any series you choose methodically – series modules always build your knowledge and skills progressively and you will gain most by ‘sticking to the plan’.
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