Chord tensions

[Jean-Michel G]

In the last few lessons, Brian often refers to tricks and ways to embellish chords by means of higher extensions.
Let’s have a look at the theory behind that.

General aspects
In any chord, the root, the third, the fifth and the seventh are the chord tones (the third and the seventh may be minor of course, and the fifth may be diminished).
Everything else is a potential tension (particularly the 9, 11 and 13) that you can add while playing rhythm or lead, provided it doesn’t clash with the melody.
Adding those other notes will inevitably create dissonances, and we have two somewhat conflicting requirements:
1) the tension should last at least one beat, otherwise it will just be a passing note and it won’t count as a tension
2) the tension should remain “musical” so we will need a criterion to decide what is musical and what is not, that is to say what notes we keep (the available tensions) and what notes we avoid (the avoid notes)

When you add tensions, the chords quickly become difficult or even impossible to play on a guitar, so you will have to ditch notes. In most cases, you’ll want to keep the third and the seventh of the chord (the guide tones) because they define the chord. The root and the fifth are less important.

It is important to understand that tension notes are added to the chord and don’t replace chord tones. For example, (D, F#, A, C, E) is a D9, but (D, E, A, C) is a D7sus2.

Tensions on non-dominant chords.
– First write down all the chord tones
– All the notes a semitone above the chord tones are avoid notes
– All the notes two semitones above the chord tones are available tensions
– All the remaining notes are avoid notes

For example, let’s take Em7
– the chords tones are E, G, B, D
– the avoid notes are F, G#, C, D#
– the available tensions are F#, A, C# (9, 11, 13)
– A# is an avoid note

Other example: Amaj7
– the chord tones are A, C#, E, G#
– the avoid notes are A#, D, and F
– the available tensions are B, D# and F# (9, #11, 13)
– C and G are avoid notes

But we also need to look at the function of the chord or, equivalently, at the key. If the Em7 chord is the iii chord (we are obviously in C Major), the notes F# and C# don’t belong to the key. So if we want to play “in”, we better avoid these two notes.
On the other hand if that Em7 is the vi chord (we are in G Major), only the C# is questionable.
In D Major Em7 is the ii chord and there is no problem at all.

Tensions on dominant chords.
Those are a bit different because they already contain a strong dissonance (the tritone), which is inherent to that chord type. That tritone sits between the third and the (flat) seventh of the chord, in other words between the guide tones. So, in order to preserve the quality of the dominant 7th chord we usually avoid clashing with those tones.
– Write down the chord tones
– the guide tones (3 and 7) plus one semitone are avoid notes
– all other notes are available tensions

For example: C7
– C, E, G, Bb
– F, B are avoid notes
– everything else is an available tension

Have fun with all those dissonant jazz tones!

[charjo]

Thanks for your thoughtful post. I think I understand now why major chords have a #11 extension and minor chords have an 11 extension. Also, all the dominant 7 chord available tensions and avoids was interesting.
I was trying to understand Brian’s example in EP 487 of sliding a minor triad up 2 frets and even 3 frets within the context of a minor jam. I can see the A minor triad goes to a B minor triad and is within the key of A minor but I didn’t get the 3 fret version. I think your explanation of what constitutes a passing note(s) clears that up for me.
Is it useful when thinking how a chord functions within a key to think of it’s root note modal nature. For example the Em7 in the key of C would be phyrgian and, therefore, the 2 and 6 intervals would be flat in any diatonic extension?
John

[Martyn in France]

I’ve been here for a while … 2011. And I used to contribute regularly, but not much now. But I’m still here because of people like you Jean-Michel. I really really appreciate all you do with these theory posts. These days I play more by instinct than carefully thought-out solos, but I can relate to what you say each time to what I’m playing. It’s like I’m able to apply the theory after the soloing. So thank you for all you’re doing here.
Recently I saw you were a little bit disappointed by the small response some of your post were getting, but don’t be!! There are many here who really love what you’re doing, but sometimes we are a bit intimidated by the complexity (or perceived complexity).
And when you gather it all together and publish the book on guitar theory, I have my credit card ready!!

[Richard W]

Great post, Jean-Michel! I’ve never seen tensions broken down like this so systematically. I’ll have to spend some time with my looper and your post nearby.

[Jean-Michel G]

Thanks for your nice words, guys! It’s nice to know that those theory posts are somewhat useful!

The jazz guitarist Steve Khan has a complete pentatonic-driven approach to chord tensions. He wrote a book about it called “Pentatonic Khancepts”.

For example, on major chords he suggests playing the minor pentatonic scales built on the degrees 3, 6 or 7 or even 2.
Let’s take the chord Ebmaj7 (Eb, G, B, D):
The degree 3 = G, 6 = C, 7 = D
– Playing the minor pent rooted on G (G, Bb, C, D, F) introduces the 9th (F) and the 13th (C)
– Playing the minor pent rooted on D (D, F, G, A, C) introduces the 9th (F), the #11th (A) and the 13th (C)
– Playing the minor pent rooted on C (C, Eb, F, G, Bb) introduces the 9th (F) and the 13th (or 6th) (C)

You’ll find quite a few posts on YouTube that discuss similar approaches.
I have to confess that I am personally not very fluent with this approach, but I am not a jazz guitarist. But I thought I’d mention it so you can spend some time exploring the concept.

[Richard W]

I actually have that book, never spent much time with it, but I’ll take another look.

I notice that a cool thing about those minor pent scales is that they introduce the tensions without introducing any avoid notes, which I guess makes them “safe” to use.

[brian-belsey]

Hi J-M, I have only just noticed this. I’m glad I didn’t miss it altogether! Tension in chords and the whole issue of dissonance is fascinating in its expressiveness and, often, its beauty. It’s very useful to see these issues surrounding non-dominant and dominant chords set out in detail.

I believe it is true to say that ideas about dissonance and harmony change and develop over time and sometimes renaissance music in particular can strike us as a bit odd here and there. I imagine they would find some of our harmony displeasing and unsettling.

I find dissonance so intriguing and attractive and wonder if the boundaries involving avoid notes can be pushed further. I am not aware of any examples of minor second dissonances being used but I suggest this could express anguished tension!

[Jean-Michel G]

Hi Brian,
You are absolutely right about how musicians used to look at dissonance and how they look at it today.
The post above is actually rather contemporary and jazz-oriented; in the Common Practice era many contemporary “mundane” dissonances would have been absolute no-no’s… except maybe in the Romantic period.

An interesting aspect is that in the Common Practice era they didn’t use our contemporary equal temperament and therefore some chords (even triads) that we find perfectly consonant today were perceived as harsh and unsettling back then. That was definitely part of Bach’s musical vocabulary.

As for minor seconds, I’m sure there must (horror) film scores that use them! 😉

[brian-belsey]

The point you make about contemporary equal temperament is interesting, J-M. I hadn’t thought of this, but this obviously suggests some degree of objectivity about different attitudes in the past and not simply just changing harmonic tastes over time.

[Jean-Michel G]

That’s an interesting question, but it’s also very complicated and I am by no means an authority.

A significant part of our attitude towards (and our perception of) dissonance is probably mainly cultural. We tend to like things that we hear often and we try to like things because others seem to like it. Also, what we Westerners call dissonance is not perceived at all as dissonant by other cultures on the planet. So much of this is probably mainly subjective.

But on the other hand, I believe that music has real physical power. There is that famous story of Janet Jackson’s “Rhythm Nation” that used to destroy the hard drive of the laptops the song was played on…
So maybe Consonance/dissonance has some sort of resonating effect on us human beings, depending on the frequencies being superposed. That would certainly be objective.

By the way, the theme of “Jaws” uses minor seconds, although only melodically I think.

[brian-belsey]

J-M, your comment about minor seconds in the Jaws theme reminds me of that terrific little Fantasia by Mudarra, the one where he said there were some false notes but when played well they do not sound bad! I have been promising myself for a long time I would practice this thoroughly and learn it properly!

I am sure you are right about the extent of cultural influences and I agree about the likely physical power of music.

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