Triad Pairs are a common tool amongst both modern jazz players and composers of the early 20th century. The idea is self-explanatory. Put simply they are two triads paired together that do not share a common tone.
For example check out these triads:
By nature of them being triads (3 notes each) and not sharing a common tone we get a grand total of 6 unique pitches or a hexatonic scale.
The notes of the G are the black notes the Am are the hollow notes.
One of the interesting things here is that we have a “key” derived from two harmonies. Each note in the resultant scale can be harmonized with either one or the other chord in an alternating fashion. This gives us a harmonic yin and yang situation where each chord contrasts the other one in an equal and opposing manner.
Tonality here is completely relative to context. If this scale were played over an A minor chord the notes of the A minor would obviously sound very inside the harmony while the notes of the G chord would give contrast. Conversely, if this scale were played over a background of a G major chord the notes of the A minor would now sound “outside” while the notes of G would be “inside”.
“Okay, great… So what key is this in?” seems to be a common question that comes up at this point. Well that depends. (How’s that for a non-answer?) Because there are only six tones in our scale we can’t really define it in terms of a traditional seven tone scale (major/minor, melodic minor, etc).
This hexatonic scale here doesn’t give us enough information to derive it’s seven note mode, but we can narrow it down. If we look at what pitches are missing we will see that there are no F’s of any kind. This is significant because if the F’s are natural we would be in A natural minor, but if the F’s are actually F#’s that would put us in A dorian. In relation to G we would either be in G mixolydian with F naturals and G major with F#’s.
This is what makes triad pairs interesting to my ears. They omit one note out of any seven tone scale or two or more notes out of eight tone or longer scales. By leaving out a note or two triad pairs create a concise harmonic framework for us to explore. Now instead of having at least seven different harmonies per key we have only two. One is “inside”. The other is “outside”. Both come together to create a harmonic symbiotic relationship that is easy for our ears to hear no matter how complex our triad pair might be.
How can we create other triad pairs?
Triad pairs can be derived from any traditional scale by pairing any two triads a step apart. For example, continuing with our example above let’s say they are the I and ii chord in G major. That would give us the hexatonic scale we saw above.
which we could harmonize as:
This combination gives us a soulful, gospel flavored sound. It’s almost pentatonic except for the added “Fa” or 4th scale degree thanks to the A minor. As mentioned before the note that’s omitted in this example is the F#. More on that in a bit.
One last thing: As practicing guitarists let’s try to work every possible inversion and voicing of these chords that we can. This is really beneficial not just sonically but also in developing our ability to “see” every note in a given chord all over the fretboard.
Here is this same example with open voiced triads:
Try playing chord scales up and down the neck on the same strings using triad pair voicings. You may use other strings if you find a particular voicing or inversion too difficult to stay strictly on the same string sets.
Now try playing these chord scales across the neck horizontally or within one position.
Let’s try another triad pair:
Here’s our ii and iii chord in G major. This is an interesting sound to my ears. The two minor chords a whole step apart sound somewhat exotic, but as you can see they are right at home in G major.
And open voiced:
The note omitted here is the G. We are in the key of G major and there are no G’s. That’s fun right? Here’s the way to know what note will be omitted from a traditional 7 note scale such as a major/minor or any church mode, melodic minor, or harmonic minor:
It’s always the 7th of the lower triad. So in our recent example the lower triad between Am and Bm is Am. The 7th of Am in the key of G major is the note G. Therefore there will be no G’s in this triad pair.
Or another way to state this would be:
It’s always the note one scale degree under the lower triad. Again in our recent triad pair Am is the lowest of the two. In the key of G major the note just below A is G therefore the G is the omitted note.
Here are a few more examples to get you going:
iii and IV
IV and V
There you have it. That’s the general concept. Again, practice these triads in all inversions and try to make music out of them. Because all of the notes in these hexatonic scales have built in harmonization it makes it easy to play harmonized melodies and chord solos.
Here’s one application in a more gospel style. You can definitely hear how triad pairs can be used to harmonize a melody. Piano players have been doing this for years!!
Here’s another piece to explore triad pairs. This one employs mostly open voiced triads.
If these chord voicings are tough or unusual for you don’t get too frustrated. They were for all of us at one point or another. If you’re unsure of how to voice triads all over the neck–or if you don’t know what I mean by “voicing” triads let me know. I’m here to help.
Thanks for stopping by. Have fun working through these triad pairs. We’ll be expanding on this concept in much greater depth over the next few weeks so be sure to check back in here for more.
Now go play something new today.
-PostModernGuitarist
PostModernGuitarist 