Module 14: Modern harmony and rhythmLesson 2advanced⏱ 90 min + 20 min daily for two weeks

Upper-structure triads

Put a major triad on top of a dominant chord's guide tones to produce exact tensions, learn the six triads that matter over G7 with every tension verified, voice them on the guitar, and build lines from them.

Why triads on top

Ask a pianist how they voice an altered dominant and the answer is usually "a triad in the right hand over the 3rd and 7th in the left". That is an upper structure: a plain major triad placed above the guide tones of a dominant chord. The guide tones fix the chord's function (it is still G7, it still wants to go to C); the triad adds three more notes, and because a triad is such a strong, familiar shape, the ear hears those notes as a single colour rather than three separate tensions. Upper structures are how arrangers write 13#11 and 7#9b13 chords for a horn section, how pianists voice them, and, once you know where they sit on the neck, how guitarists get the same sound with five strings.

They are at least as useful for improvising. A line built from an A major triad over G7 is instantly recognisable as a 13#11 sound, and it is a shape you can play fast, rather than a scale you have to think through. This lesson builds the table of triads over G7, verifies every tension, voices them, and turns them into lines over the ii–V–I. You need the rootless and altered shapes from Extensions, rootless voicings and altered dominants and comfortable triad shapes on strings 3-2-1 from Triads.

The six triads over G7

Over G7 the guide tones are B (the 3rd) and F (the 7th). Put any major triad above them and ask what each of its three notes is in relation to G. Six triads produce useful, consistent colours; the table lists them with the tension each note becomes and the chord symbol a chart would use. Every row was checked against the engine, and the generated tables below the summary show the notes of both the triads and the resulting chords.

Two things to notice. First, the triads come in pairs a whole step apart that share a scale: A and E are both in the dominant diminished (half-whole) scale with Bb and Db; Db and Eb are both in the altered scale. That is the seed of the triad pairs lesson. Second, the Ab triad includes C, the 4th of G, which clashes with the 3rd unless the voicing omits the B; it is really an upper structure over a G7sus4 shell, and we treat it separately below.

Voicing them on the guitar

The guitar version uses a two-note shell, the 7th and 3rd on strings 5 and 4, with the triad on strings 3-2-1. Keeping the shell fixed at frets 8-9 puts all six triads within a four-fret span, which is the practical limit for a five-note chord. The triad shapes are ordinary close-position triads in whichever inversion falls under the hand.

Combined, shell plus triad, each becomes the full five-note voicing. The engine checks every note of these shapes against the resulting chord symbol.

\tempo 60
.
\ts 4 4
(8.5 9.4 9.3 10.2 9.1).2{ch "G13#11" txt "A triad"} (8.5 9.4 10.3 11.2 10.1).2{ch "G7#9" txt "Bb triad"} | (8.5 9.4 10.3 9.2 9.1).2{ch "G7b9#11" txt "Db triad"} (8.5 9.4 8.3 8.2 6.1).2{ch "G7#9#5" txt "Eb triad"} | (8.5 9.4 9.3 9.2 7.1).2{ch "G13b9" txt "E triad"} r.2 |

The Ab triad is the odd one out. Its C is the suspended 4th (11th) of G, which the engine's G7b9b13 symbol does not contain, so this block declares allow=C and you should hear why: with the B in the shell the C rubs against it a half step away, which is the point of the sound in Spanish-tinged or modal contexts, and a problem in a straight bebop ii–V. Drop the B (mute string 4) for the pure sus version.

\tempo 60
.
\ts 4 4
(8.5 9.4 8.3 9.2 8.1).2{ch "G7b9b13" txt "Ab triad"} (8.5 x.4 8.3 9.2 8.1).2{txt "no 3rd"} |

Choosing an upper structure

Which triad to use is a decision about the melody and the resolution, not a matter of taste alone. Three guidelines from arranging practice:

• Match the melody note. If the tune's melody on the dominant is the 13th, the A triad (13#11) or the E triad (13b9) contains it and the altered triads do not; if the melody is the b13 or #9, the Eb triad is the one. An upper structure that fights the melody note sounds like a wrong chord, however correct the theory.
• Match the resolution. The A and Db triads both contain the #11 (C#), which wants to move up to D, the 9th of Cmaj7: use them when the top voice resolves upward. The Eb triad's b13 and #9 want to fall to the 5th and 9th of C: use it when the top voice resolves downward. The E triad is the most consonant with a plain Cmaj7 resolution because its 13th becomes the 3rd of C.
• Match the player next to you. Over a pianist who is already voicing altered chords, play only the triad (three strings) or nothing; over a bass player alone, the full five-note shape with the shell is what fills the space.

Hear each voicing before you use it: play the shell, sing the three notes of the triad one at a time, then play the chord. Within a week the colours become as recognisable as major and minor.

Voice leading through the ii-V-I

Upper structures earn their place when they resolve. In each of the three ii–V–I cells below the ii chord is a rootless Dm9 at the same frets, the V chord is one upper structure, and the I chord is whatever lands closest. Notice how little the hand moves: the entire cell lives between frets 7 and 11.

\tempo 100
.
\ts 4 4
(8.5 10.4 9.3 10.2).2{ch "Dm9"} (8.5 9.4 9.3 10.2 9.1).2{ch "G13#11"} | (7.5 9.4 7.3 8.2).1{ch "Cmaj9"} | (8.5 10.4 9.3 10.2).2{ch "Dm9"} (8.5 9.4 10.3 9.2 9.1).2{ch "G7b9#11"} | (7.5 9.4 7.3 8.2).1{ch "Cmaj9"} | (8.5 10.4 9.3 10.2).2{ch "Dm9"} (8.5 9.4 8.3 8.2 6.1).2{ch "G7#9#5"} | (7.5 7.4 7.3 8.2).1{ch "C6/9"} |

Lines built from upper structures

To improvise with an upper structure, arpeggiate the triad over the dominant bar and touch the shell notes (3rd and 7th) to keep the dominant function audible. The three lines below each take a different triad. They are checked note for note: the ii bar against Dm9, the V bar against the specific chord symbol the triad produces, and the I bar against the resolution chord.

\tempo 140
.
\ts 4 4
:8 7.4{ch "Dm9"} 10.4 7.3 9.3 10.3 7.3 10.2 8.1 | 9.1{ch "G13#11"} 10.2 9.3 10.2 9.3 11.4 10.3 9.4 | :4 10.4{ch "Cmaj9"} :8 9.3 7.3 :2 8.2 | r.1 |

\tempo 140
.
\ts 4 4
:8 5.5{ch "Dm9"} 8.5 7.4 10.4 7.3 9.3 10.3 9.3 | 11.4{ch "G7b9#11"} 10.3 9.2 9.1 9.2 10.3 11.4 9.4 | :4 10.4{ch "Cmaj7"} :8 9.3 8.2 :4 9.3 r |

\tempo 140
.
\ts 4 4
:8 5.5{ch "Dm7b5"} 8.5 6.4 10.4 7.3 10.3 9.2 10.3 | 8.3{ch "G7#9#5"} 8.2 11.2 11.1 8.2 8.3 8.4 9.4 | :4 10.4{ch "Cm9"} :8 8.3 7.3 :2 8.2 |

How to practise lines like these:

1. Play the triad alone over the dominant bar, slowly, in every inversion you can reach without shifting, until the sound is familiar.
2. Add a shell note (3rd or 7th) at the end of the bar to point the line at the resolution.
3. Transpose the whole cell to the next key around the cycle of 4ths. The triad moves with the dominant: over C7 the 13#11 triad is D, the altered triad is Ab, the tritone triad is Gb.

Exercises

1. The six voicings over the G7 shell as written, 60 bpm, then over C7 (shell at frets 1-2 on strings 5 and 4: Bb and E) and F7 (shell at frets 6-7 on strings 5 and 4: Eb and A). Work out the triad frets yourself from the interval rule; check each against the chord dictionary.
2. ii-V-I cells in C as written, then in F, Bb, Eb, Ab, keeping each cell inside a four-fret span.
3. Lines 1-3 at 100, 120, 140 bpm; then transpose each to F and Bb.
4. Write your own line using the E triad (13b9) over G7, resolving to Cmaj7, and check it with the chord-tone rule: every note in the V bar must be G, B, D, F, E, Ab or B.
5. Blues application. Over an F blues, play the Bb-triad sound (7#9) on the I chord in bar 4, and the Db-triad sound over C7 (bar 10): work out which triads those are for F7 and C7.

Quiz