Slash Chords (3) Hybrid Chords

1. What is a Hybrid Chord?

Now, in the first session of slash chords, I explained the concept of “inversion”, where one of the chord tones (other than the root) is placed in the bass.

The final topic to be covered is the opposite pattern, where a note that is not a member of the chord serves as the bass.

When a chord is supported by an independent bass note different from the chord tones, as shown above, it is called a Hybrid Chord¹. Let’s explore the intention behind separating the upper structure and the bass.

2. Effects of Hybrid Chords

Hybrid chords can be seen as a combination of two chord functions. While “inversion” involves playing an independent bass, it still plays one of the chord tones, resulting in a cohesive whole. Hybrid chords have a higher independence between the upper and the bass, creating a unique depth that portrays different chords for each.

This is an example; the hybrid chords are used in the 3rd and 4th bars. In the 3rd bar, the bass is trying to build tension with V, but the synth on top is playing II_m7, suppressing the sense of climax.

In the 4th bar, the bass lands on the VI note. However, the upper synth shifts to V chord, resulting in a composition that feels uncertain, a mixture of landing and not landing. This technique is quite remarkable, allowing for complex sounds with ease. In particular, chords like II_m7/V or similar IV_/V are classic choices in genres like dance music and funk.

As a comparative experiment, let’s listen to a pattern where the synth on top is aligned with the bass.

IV_Δ7III_m7VVI_m

The dominant and tonic sensations are too pronounced, and the excitement is diminished compared to the previous version. Therefore, by using hybrid chords, more delicate expressions of chord colors become possible.

Examples

“Celebration” by Kool & the Gang is a great example. The “pedal point” introduced in the last session is utilized in the verse section, but that’s already a closed topic. Pay attention to the bridge section that follows (1:29).
You can find two slash chords—E♭/F and D♭/E♭. Here the song is in the key of A♭, so they’re analyzed as V_/VI and IV_/V, respectively.

Here V_/VI acts really like a Vsus4 chord, delaying the resolution timing. IV_/V functions as a softer variant of the V chord. The key point here is that the melody sings the note do (“world, come on!”). If the V chord were used, the melody would overlap with the chord tone ti from a half step above, resulting in a strong dissonance. Therefore, using the hybrid chord when the melody is on do becomes a very rational choice to avoid that.

Maybe the most famous song in funk, “September” by Earth, Wind & Fire. Again in intro, the guitar consistently playing the note A constitutes a “soprano pedal point”, but it’s not the topic here.
Listen to that, after a simple cycle of diatonic chords, a thrilling chord gets in, Gmaj9/A, which is analyzed as ♭VIImaj9/I. “maj9” is a chord we haven’t covered yet, so here’s the score.

To simplify it, it’s ♭VII/I and can be seen as a parallel minor chord. The charm of ♭VII lies in its floating quality, but when combined with the grounded bass of I, it creates a unique sound that truly resides between stability and instability.
Given that the bass is on do and there’s an accidental ti♭ in the upper, this hybrid chord somewhat resembles the secondary dominant I₇.

This could be why it smoothly connects to the next chord, IV_Δ7.

Thus in funk, the use of various hybrid chords creates a sophisticated atmosphere that is pleasing to the ear without being overly complex.

Incidental Hybrid Chords

It’s worth noting that the pattern of “the bass playing notes unrelated to the upper structure” can incidentally occur when the bass moves freely.

Here, while the upper structure forms a relaxed 1-6-4-5 progression, the bass smoothly descends like 1-7-6-5…. As a result, there is a mismatch where the upper structure is I while the bass goes to the VII and so on.

This in itself is not a bad thing; it stands as an expression aiming for the middle ground between the two chord progressions. There are places where a strong muddiness occurs due to the discrepancy between the upper and the bass, but unexpectedly, such deviations are sometimes accepted through the power of context.
Yet, incidents like this, occurring accidentally within the bass’s transitional movement, are not often specifically referred to as “hybrid chords”. The term is more reserved for instances where the chord colors are intentionally blended, as in the previous example.

3. Necessary Condition

The key to hybrid chords lies in the separation of the upper and the bass. However, for these two to be distinctly “separated”, a certain condition must be met. For instance, simply stacking C, E, G, and B together and claiming “This is a hybrid chord!” is unreasonable.

This arrangement clearly represents a C_Δ7. Even if the upper structure doesn’t play the note C at all, it is a level of a plausible voice arrangement, and it does not create a sense of disconnection to the extent of “separation of the upper and the bass”. Interpreting this as IIIm/I would be unnatural.

So, what determines the key to separation is whether the upper contains the 3^rd note from the perspective of the bass. In the example above, there is the note E, which is the 3^rd relative to the bass note C. With just this, it is already sufficient to convey a sense of cohesion as a C major chord. Therefore, if we remove this note……

This can be adequately referred to as a hybrid chord. The 3^rd note not only determines the major/minor quality of the chord but also serves as a factor that anchors the upper and the bass together².

Creating Hybrid Chords

Thinking in reverse, this implies that by omitting the 3^rd of a beautifully sounding chord, you can easily create a hybrid chord that sounds beautifully.

Here, various “muddiness” has been added to the familiar progression of 4-3-6-1. Since these additions were made with the intention of removing the 3^rd later, it might sound a bit cluttered. By removing the 3^rd of each chord from here, the separation between the upper and the bass should be achieved……

This is the result! It’s a bit of extreme case where all the chords get “hybrid”, but anyway you can confirm the sounds of hybrid chords. Initially, you might feel that the density of the sound is thin, but over time, a unique sense of separation becomes addictive, offering the charm of that kind.

---

Now, over the course of three sessions, I have introduced the usage of slash chords. From the simple idea of independence between the upper and the bass, you should now understand how many musical effects can be created.

Summary

• A “Hybrid Chord” refers to a structure where the bass takes on an independent note not present in the upper structure.
• Hybrid chords create a complex sound as if the sounds of different chords are layered together.
• By omitting the 3^rd relative to the bass, a sense of separation between the bass and the upper structure can be achieved.

Continue

---