A Brief Review of Diatonic Harmony:

In lessons 11 and 14 we covered diatonic triads and 7th chords for all major keys. In this lesson I show you how to extend these harmonies with color tones, or notes called tensions.

Before I get into the gory details, however, let's briefly review diatonic harmony to make sure we're all on the same page. Recall the key of C major:

Nothing new here. We've simply harmonized a major scale by stacking diatonic thirds on top of each other. This simple process is how one creates the seven diatonic triads for any major key and as we've covered earlier, this approach is the basis for harmony for western music.

We also learned that by adding one more note, a diatonic third above each triad, we transform each triadic structure into a "rich" sounding four-note structure called a "7th chord".

Again, this is nothing new to us, but let's see what happens when we extend these structures even further.

Tensions:

Take a look at the "one" chord for the key of C major:

As the above diagram illustrates, by "stacking thirds" on top of a C maj.7 chord, 3 possible tensions emerge: d=9, f=11, and a=13.

Notice that these 3 notes are the same 3 notes that make up a D minor triad. Remember, a 9th is just a 2nd up one octave, an 11th is a 4th up an octave and a 13th is a 6th up one octave. So it only makes sense then that a triad built on the 9th note of a C major scale is the same triad built on the 2nd degree of a C major scale, namely, a D minor triad.

This kind of abstraction (seeing tensions as triads) is useful for it enables you to think quickly in the heat of the moment, say... when you're performing. Hopefully, as you progress in your understanding of music theory, you'll naturally start to make these kinds of "connections" or "associations".

The intervals formed by this upper structure triad are called compound intervals and compound intervals are nothing more than intervals that are greater than one octave.

Now, when you play these 3 tensions (d, f, and a) over a C maj.7 chord, your ear might make some observations: the d and a notes sound "pleasant" or "consonant" while the f note sounds somewhat "harsh" or "dissonant". Why is this so? Because d and a both form major 9ths (compounded major 2nds) above chord tones while the f forms a minor 9th (a compounded minor 2nd) above a chord tone. Check it out:

d is a major 9th above c, and a is a major 9th above g, but f is a minor 9th above e. It is this minor 9th interval that brands f (from a theoretical point of view) as an avoid note when played over a C maj.7 chord.

What this means is that you want to avoid playing this note (both harmonically and melodically) in the context of a "one" chord in the key of C major. If you do play the f note, especially on a strong beat of the music, you'll wind up sounding like a hack unless you resolve the note down a half step to an e, a chord tone.

The End Result: The available (not possible) tensions for a I maj.7 chord (for a major key) are 9 and 13. Stay away from the 11th or, at the very least, exercise caution when you do play this note in a melodic context. Certainly, stay away from the 11th when you are comping, that is, when you are playing chords.

Available Tensions:

Now, if we follow this same logic and explore all possible tensions (9ths, 11ths, and 13ths) for all triads and 7th chords for a major key, the following "rules" or "available tension choices" emerge:

Yeah, this chart will take a long time to really understand. Give yourself some time to absorb it. If you're feeling overwhelmed, just look at triads first, then start to look at some of the 7th chords.

If you're really lost, here are the available tensions for all diatonic 7th chords for the key of C major. Hopefully, this will help to get you started...

A Simple Method for Cool Voicings:

Now that you understand what tensions are and some rules about which ones to use, it's time to learn how to play them on the guitar. Before we continue,however, I just want to say that in almost all cases tensions are played on the top 4 strings of the guitar (the d, g, b and high e strings). If they are voiced on the "a" or low "e" strings, they fall too close to the bass and start to sound like a bass note themselves. And that's not the point of tensions, they are color tones and should sit high on top of your chords. Afterall, they are compound intervals, that is, they should be voiced at least an octave higher than the root (or bass) note.

So here we go... a real cool way to spice up your ordinary major and minor chords is to do the following:

1. Play a good old standard (open voiced, root position) major or minor chord.
2. If the root is on the low "e" string of the guitar, find a root one octave higher on the "d" string. if the root starts at the 5th string, then find a root one octave higher on the "g" string.
3. Now, instead of doubling the root, play a note a step higher instead.
4. And voila! you've added tension 9 to your basic beginning chord... for a major chord, the voicing becomes a major (add 9), and for a minor chord, the voicing becomes a minor (add 9) chord.

Here are some examples to illustrate what I mean:

Some of My Favorite Chords:

Now here are some of my favorite chord voicings. Hopefully, some of these will help you to form some cool voicings of your own. Study the following chart well. Make sure you understand the chord tone analysis for each shape. Also, try experimenting by moving these patterns around on the fingerboard. (I always do this with new chords I learn.)

For instance, move the voicings (patterns) around in two ways:

1. Retain the intervallic structure by replacing open strings with closed strings. This is like playing an E major chord in open position and then moving it around the fingerboard as a barre chord. (Really, all chords are moveable or barre chords.)

2. Spice up the intervallic structure by keeping the fingerings the same for a particular pattern but keep the open strings open. This is like playing our E major chord in open position but then moving it around the fingerboard while keeping the low E, B, and high E strings open in each new position.

And it goes without saying that initially (before you start moving shapes around the fingerboard) you need to pay close attention to the position markings and fingerings for each chord diagram, otherwise, you might wind up playing the wrong chord.

Tension Substitution Rules:

Briefly, I want to show you how to add tensions to the drop-2 and drop-3 chord voicings. It's actually, quite simple. Consult the following list:

• 9 for 1
• 11 for 3 or 5
• 13 for 5
• 6 for 5 or 7

For instance, look at the following voicings:

The first inversion C maj.7 chord (a drop-2 voicing) becomes a C maj.7 (9) (or a C maj.9) chord using the "9 for 1" rule. Do you notice that the second voicing looks suspiciously like an E-7 chord? I find this terribly interesting. In fact, in a later lesson I'll explore some of the consequences of this phenomenon.
 
 
 

In the preceding diagram, the root position A-7 chord (a drop-3 voicing) becomes an A-7 (11) (or an A-11) chord using the "11 for 5" tension substitution rule.

Blues For Alice:

And to wrap up, here are some chordal exercises to further illustrate how tension substitutions can be applied to drop-2 voicings using the rules presented above. The exercises are based on a Charlie Parker tune called Blues For Alice, a blues in F. Here's the chart (lead sheet):

(By the way, that's an A7(b9) chord in the second measure. That nine looks a little like a seven.)

Now, before you muddle your way through these changes make note that most, if not all of the following voicings, can be played on the 4 middle strings of the guitar - the 5th, 4th, 3rd, and 2nd strings. To find the fingerings for a voicing, start with the lowest note first (on the 5th string), then work each higher note on the next higher string until finally, you find the lead (the highest note of the chord) on the 2nd string. It will take some time, but it's totally worth your while and within the realm of possibility.

Notice in measure 3 the second chord, the G7(b5), is also a voicing for a Db7(b5). This kind of substitution is actually quite common in music and is referred to as a tritone substitution. It works like this: take a dom.7 chord, say G7. Now, to substitute it, go up a tritone from the root and play another dom.7 chord - in this case a Db7 chord. Interestingly, you'll notice that the 3rd and the 7th of each chord will "switch." Check it out:

G7 = G, B, D, F

Db7 = Db, F, Ab, Cb

The "B" is a "3rd" in G7, but it is a "b7" in Db7. ("Cb" is an enharmonic spelling for "B".) The "F" is a "b7" in G7, but it is a "3rd" in Db7. And you know what they say (whoever the f#%! they are) about a picture being worth a thousand words:

And as the Charlie Parker tune illustrates above, the tritone substitution works for a dom.7(b5) chord as well, but with a slight difference. The roots and b5's of the two chord switch. Check it out:

G7(b5) = G, B, Db, F

Db7(b5) = Db, F, Abb, Cb

Another cool thing: you can get by by playing only roots, 3rds, and 7ths for any seven chord. The 3rd and 7th of any chord are called guide-tones. These notes, more than any other notes in the chord, tell the listener what harmony you are playing. That is, all you really need to express a seven chord is its 3rd and its 7th. You don't even really need the root! Using the 3 note chord forms above, you should find the voicings for the following chords:

maj.7, min.7, dom. 7 (already shown above), min.(b5), and so on. These 3-note voicings were covered in the 3 Note Motifs lesson (the 3-5 and 7-4 motifs), but some things are worth repeating.

Continuing with our analysis... in measure 4 the first chord, a C-9 can be substituted for an Eb maj.7 chord and vice versa. And this should make good sense since Eb major and C minor are relative major/minor keys. Remember lesson 18, the lesson on diatonic substitution? It's all coming together, no?

In measure 5 the first chord form functions as a Bb7 chord, but this voicing can also make a nice E7 altered chord if you were to play a low E in the bass. By the way, an altered chord is a dom.7 chord with any of the following tensions: b5, #5, b9, #9.

Now for a second time through the progression...

And here are two more times through. The last example (the forth time through the progression) happens to be the Berklee College of Music Chord Lab 3 midterm exam I took back in '92. If you can play these chords at the same speed Charlie played his tune, you kick major ass. Good luck.