Modern Hollywood Progression – Chords a Tritone Apart – Pt.1

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Sci-Fi, Unfamiliarity, Outer Space: Major Chords a Tritone Apart

(Previous Post: “Hollywood Chords: The Most Popular Film Music Composition Technique.”)

Our next two-chord structure involves two major chords a *tritone apart. A tritone is equal to the distance of six semitones, also known as an augmented 4th or a diminished 5th. Some examples of tritone intervals include C – F♯, or A♭ – D, or F – C♭ (see Fig. D).

This type of chord motion (two major harmonies a tritone apart) often sounds surprising and unexpected. Each harmony sounds “outside the key” in relation to the other, making each chord change sound disruptive and highly dramatic. In some contexts, this progression sounds musically colossal.

This two-chord structure often appears in films and games in the sci-fi and fantasy genres. We hope you find it a valuable and reliable technique for conjuring the unexpected. In the following examples, we explore a couple of different treatments for this composition technique.

Fig. D  Examples of Tritone Intervals

Musical Examples with Tritone Chord Progressions

– Gustav Holst, “The Planets – Ⅱ. Mars & Ⅲ. Mercury” (1916)
– John Williams, “TV Reveals,” Close Encounters of the Third Kind (1977)
– Jerry Goldsmith, “Main Title,” Star Trek: The Motion Picture (1979)
– James Horner, “Main Title,” Star Trek Ⅱ: The Wrath of Khan (1982)
– James Horner, “Genesis Countdown,” Star Trek Ⅱ: The Wrath of Khan (1982)
– Basil Poledouris, “Brainbug,” Starship Troopers (1997)
– Howard Shore, “The Prophecy,” Lord of the Rings: The Fellowship of the Ring (2001)

Theory in Depth) Tritone
The tritone is also nicknamed the “devil’s interval.” In the classical music world, when two major chords a tritone apart are played together, they form a polychord known as the “Petrushka chord,” due to their notable appearance in Igor Stravinsky’s ballet Petrushka.

Ex. 2-3-A Major Chords a Tritone Apart Ⅰ  

Tips) Distance Between Inverted Chords
Ex. 2-3-A is the first example in this chapter to use chord inversions. Since the treble clef chords are not all in root position, it may not appear that the chords are spaced tritones apart. Nonetheless, the distance between the roots of the chords (D and A♭) is a tritone.

Analysis of Ex. 2-3-A

Ex. 2-3-A is, essentially, a chord outline. There are two fundamental concepts at work here. First, the harmony is based on two chords positioned a tritone apart: D major and A♭ major. In the first four measures, we simply alternate between them. Second, we rearranged the chord tones to create inverted harmonies, resulting in a rising shape over four measures.

The upper staff consists of triads, while single notes fill out the lower staff. The slashes in the chord names help describe the non-root notes in the bass. For instance, in m. 2, the chord symbol A♭/E♭ expresses that the harmony is A♭Maj while the lowest note (in the bass) is an E♭. We carefully chose our chord inversions in the treble such that the topmost note ascends over the four measures (F♯, A♭, A, C). In fact, all four notes in both staves ascend, except for the lower two notes in m. 4.

Using piano alone, we can already hear the somewhat unexpected nature of this chord progression. The rising shape makes our chord progression more interesting and helps us tell a story with mere chords. Now let’s see what happens when we develop our outline using rhythm and orchestration to create a grand, larger-than-life piece.

Theory in Depth) Voicing Chords and Ascending
In mm. 1-3 of Ex. 2-3-A, we made all four of our chord tones ascend while changing the harmony. You can achieve this by ascending one of the chord tones and maintaining the same “voicing” (note arrangement) from chord to chord.
For instance, in m. 1, we used the following pattern (from bottom to top): a single note in the bass (D), then skip a chord tone (F♯), then a triad in the treble clef using the next available notes (A-D-F♯). We used the same pattern in the next measures. In m. 2: the bass note moves up to E♭, then skip the next chord tone (Ab), then a triad in the treble clef using the next available notes (C-E♭-A♭).

Ex. 2-3-B Major Chords a Tritone Apart Ⅱ (Orchestrated)  

Analysis of Ex. 2-3-B

Ex. 2-3-B uses the same two-chord structure, though we made a few adjustments in expanding our piece. In mm. 1-2, staccato winds and strings (in the upper register) alternate between quarter notes and eighth note triplets, imbuing our chord progression with a rollicking rhythm. Snare drum also reinforces this rhythmic pattern throughout. The top notes of the winds and strings in mm. 1-3 (A, C, D) correspond to the bottom notes of the triads from Ex. 2-3-A.

Contrasting with our last example, the bass instruments play the root of each chord, meaning all our harmonies are now in root position. Bassoon and low brass fill the lower register with whole note chord roots (❶). Meanwhile, low strings (cello/contrabass) accent beats 2 and 4 of each measure with chord roots. These roots in the bass showcase the striking tritone movement of our two-chord structure.

In our next example, we experiment by changing the bass again – this time, by exploring the use of a pedal point.

Ex. 2-3-C Major Chords a Tritone Apart Ⅲ (Orchestrated with Bass Pedal Point) 

Analysis of Ex. 2-3-C

Ex. 2-3-C is the exact same passage as Ex. 2-3-B, except now all the bass instruments (bassoon, low brass, cello, and contrabass) play an A pedal point throughout (❶). This simple choice profoundly affects the mood of the composition. Every D major harmony now sounds inverted and somewhat unresolved, since the low A is the fifth of that harmony. In turn, every A♭major chord now sounds intensely dissonant. The low A in the bass fights with the otherwise consonant A♭ harmony above (❷). All of this persistent, unresolved tension brings urgency to our composition. We feel that the stakes are high, that the situation is dire.

Furthermore, if you are familiar with the harmonic series, consider the first several partials of the low A pedal point: A, E, A, and C♯. The bassoon, strings, and low brass (which play the pedal point) are sufficient to create the rich harmonic profile for these partials. Consequently, every note of the A♭ major triad is a half-step (or minor 9th) away from these partials, which might explain why this combination is particularly dissonant

In short, our bass pedal point amplifies the drama. Our piece now combines unexpected chord changes, rhythmic energy, and harmonic dissonance. These ingredients create the sound of a daunting challenge that is an essential part of so many sci-fi and fantasy soundtracks.

Stacking Two Chords a Tritone Apart – Jazz Harmony

In the examples above, the harmonies DMaj and A♭Maj seem unrelated, making every chord change unexpected and exciting. However, we can find a deeper connection between these two chords through the lens of jazz harmony.

Suppose that we stack the two chords vertically: one in root position, and the other inverted above it (See Fig. E). In doing so, our stacked chords sound like a dominant 7th chord with tensions. The extensions (or “tensions”) of a dominant 7th chord include ♭9, ♮9, ♯9, ♯11, ♮13, and ♭13. 

In Fig. E, the first stacked chord (D major triad) forms the foundation. The three notes of the inverted A♭ triad above relate to the D triad below. The C becomes the ♭7, the E♭ becomes the ♭9 tension, and the A♭ (enharmonic G♯) is equivalent to the ♯11 tension. Therefore, we label this chord as D7♭9♯11. In the jazz standard, Days of Wine and Roses, we often hear the second chord harmonized this way.

Fig. E  Analyzing D and A♭ triads using jazz harmony

Furthermore, the combined notes of these stacked chords form the following scales when placed in sequential order:

D triad with A♭ triad stacked above: D – E♭ – F♯ – A♭ – A – C  

A♭ triad with D triad stacked above: A♭ – A – C – D – Eb – F♯

Interestingly, if you account for enharmonic equivalents, both sequences of notes form the exact same scale formula: Root, T♭9th, 3rd, ♯11th, 5th, and ♭7th (see Fig. F). In other words, either scale is compatible with either stacked chord, and they may be used interchangeably.

Fig. F  Scale Formula of the Combined Two Chords

This is an excerpt lesson taken from [Study Pack] Two Chord Structure – 3rds apart. Full video lessons, PDF scores, and MP3 audio files on this topic can be found here:  Creating Mood Instantly with Two-Chord Structures.