Of Moonlight and Bridges, Part 2

In the previous post I introduced what I'm calling the Bridge Chord and the Moonlight Chord. In the process I made lists of their hypermodes as if it was obvious why I was doing that; in this post we'll peer a bit deeper into the waters we've disturbed and see what we can make out.

To recap: Bridge is 1-2-b3-#4-5-6, a minor 6 pentatonic with a raised 4 and added 2. You can also "see" it as a minor triad with a major triad a whole tone above (e.g. C minor plus D major). Moonlight is 1-b2-b3-#4-5-b7, which is a regular minor pentatonic with a raised 4 and, this time, a b2, or a minor triad with a major triad a tritone away (e.g. C minor plus F# major).

I want to look at two things in this post. First, what if you play both at the same time? Second: What if you take a pair of them some interval apart? The first question is actually a special case of the second, since it's playing Bridge and Moonlight a unison apart (an interval of no semitones).

This post will be a bit of an info-dump but I'll include some notes on which options seem most promising.

Here are CAGED diagrams for these, which I omitted last time but I feel like they're essential (for me) when it comes to the more advanced applications. That's because we'll often find ourselves in a particular position (for example, playing a particular voicing of Am7) and want to grab one of these scales based at another root without having to jump out of the position we're in.

That means we need to learn them in all positions eventually, but to start with we'll need at least three. I tend to learn the C, A and E shapes (the first, second and fourth diagrams in the strip) first, but it doesn't really matter which you gravitate towards. The idea is to pick three that just about cover the fretboard, aiming to fill in the gaps later. CAGED, or any "system" of fingerings really, is about putting some rungs on the ladder, it's not supposed to be the final destination.

Moonlight

Bridge

Bridge and Moonlight Together

Blending the notes of Bridge and Moonlight yields 1-b2-2-b3-#4-5-6-b7. This is an eight-note scale that looks like Dorian #4 (1-2-b3-#4-5-6-b7) with an added b2. Dorian #4 is a mode of Harmonic Minor, and we saw that scale crop up in the last post for the same reason.

That's almost all there is to say, but note that C Bridge and C Moonlight overlap exactly on their C minor triads but add both the D major and F# major triads. It might be useful to look at what we get from just those two triads, disregarding the C minor at the root which is easy enough to find anyway. These two triads overlap on the F# that's the third of D and the root of F#, so altogether they make the pentatonic set D-F#-A-A#-C#; b2-2-#4-6-b7.

If we think of this as something we're playing "over" (or "in the context of") Cm, we can add the C back in to get the hexatonic 1-b2-2-#4-6-b7, which is pitch class set 6-15. This might be worth a bit more investigation or it might not, I don't know at this point. For now, here are the CAGED fingerings for this hexatonic in case you want to experiment with it:

Moonlight Modes and Hypermodes

The rest of this post is about what happens when we play Moonlight or Bridge somewhere that isn't the root. That yields a lot of information so it's helpful to find some kind of signpost. Thinking in a triadic harmonic context, it's worth noticing which of these contain important structures at the root such as major or minor thirds, altered or unaltered fifths and some kind of seventh. In very crude terms this tells you what kind of chord the idea "works over", but it may be more fruitful to think of this as giving a familiar anchor-point for us when we're trying to explore these sounds. I've included a brief note about that in the list but your mileage may vary, and in an atonal setting you might not care much about these observations at all.

Besides Moonlight itself, the modes are as follows:

• Moonlight at 2 = ['1', '2', 'b3', '4', 'b6', '6'] (6-z50) [Minor, no 5 or 7]
• Moonlight at 4 = ['1', 'b3', '4', 'b5', 'b6', '7'] (6-z50) [Diminished Maj 7]
• Moonlight at b5 = ['1', 'b2', '3', 'b5', '5', '6'] (6-z50) [Major 6]
• Moonlight at 6 = ['1', 'b3', '3', '5', '6', 'b7'] (6-z50) [Bluesy Dominant]
• Moonlight at 7 = ['1', '2', '4', 'b5', '6', '7'] (6-z50) [Suspended]

The hypermodes arise when we play Moonlight displaced away from the root in such a way that the root is not longer in the scale; in this case it usually makes sense to add the root back in, giving us the seven-note scales I listed in a different way last time:

• Moonlight at b2 = ['1', 'b2', '2', '3', '5', 'b6', '7'] (7-z18A) [Major 7]
• Moonlight at b3 = ['1', 'b2', 'b3', '3', 'b5', '6', 'b7'] (7-31A) [Altered Dominant]
• Moonlight at 3 = ['1', '2', '3', '4', '5', 'b7', '7'] (7-29A) [Major / Dominant 7]
• Moonlight at 5 = ['1', 'b2', '2', '4', '5', 'b6', 'b7'] (7-29B) [Suspended]
• Moonlight at b6 = ['1', '2', 'b3', 'b5', 'b6', '6', '7'] (7-31B) [Diminished Maj 7]
• Moonlight at b7 = ['1', 'b2', '3', '4', 'b6', 'b7', '7'] (7-z18B) [Major / Dominant 7]

Bridge Modes and Hypermodes

We'll do the same exercise with Bridge. Again we'll start with the modes:

• Bridge at b3 = ['1', 'b3', '4', 'b5', '6', 'b7'] (6-z29) [Minor 7]
• Bridge at 4 = ['1', '2', '4', '5', 'b6', '7'] (6-z29) [Suspended / Major 7]
• Bridge at b5 = ['1', 'b2', 'b3', 'b5', 'b6', '6'] (6-z29) [Minor 6]
• Bridge at 6 = ['1', 'b3', '3', 'b5', '6', '7'] (6-z29) [Major 7]
• Bridge at b7 = ['1', 'b2', '3', '4', '5', 'b7'] (6-z29) [Dominant 7]

We can then look at the hypermodes, expanded as above to include the root:

• Bridge at b2 = ['1', 'b2', 'b3', '3', '5', 'b6', 'b7'] (7-32B) [Altered Dominant]
• Bridge at 2 = ['1', '2', '3', '4', 'b6', '6', '7'] (7-32A) [Major 7 #5]
• Bridge at 3 = ['1', 'b2', '3', 'b5', '5', 'b7', '7'] (7-19B) [Major / Dominant]
• Bridge at 5 = ['1', 'b2', '2', '3', '5', '6', 'b7'] (7-25B) [Dominant]
• Bridge at b6 = ['1', '2', 'b3', '4', 'b6', 'b7', '7'] (7-25A) [Minor/Major 7, no 5]
• Bridge at 7 = ['1', 'b2', '2', '4', 'b5', 'b6', '7'] (7-19A) [Suspended]

Grouping by "Application"

I think as a way to explore this wider material it might help to group the modes and hypermodes into families, each of which as the same "anchor point". Any such family might suggest interesting material on a given chord quality or, setting aside simple-minded changes playing, an expanded harmonic context of some kind or even just a shared melodic backbone.

• Minor
  • Moonlight at 2 = ['1', '2', 'b3', '4', 'b6', '6'] (6-z50) [Minor, no 5 or 7]
  • Bridge at b3 = ['1', 'b3', '4', 'b5', '6', 'b7'] (6-z29) [Minor 7]
  • Bridge at b5 = ['1', 'b2', 'b3', 'b5', 'b6', '6'] (6-z29) [Minor 6]
  • Bridge at b6 = ['1', '2', 'b3', '4', 'b6', 'b7', '7'] (7-25A) [Minor/Major 7, no 5]
• Major 7
  • Moonlight at b5 = ['1', 'b2', '3', 'b5', '5', '6'] (6-z50) [Major 6]
  • Moonlight at b2 = ['1', 'b2', '2', '3', '5', 'b6', '7'] (7-z18A) [Major 7]
  • Bridge at 6 = ['1', 'b3', '3', 'b5', '6', '7'] (6-z29) [Major 7]
  • Bridge at 2 = ['1', '2', '3', '4', 'b6', '6', '7'] (7-32A) [Major 7 #5]
• Dominant 7
  • Moonlight at b3 = ['1', 'b2', 'b3', '3', 'b5', '6', 'b7'] (7-31A) [Altered Dominant]
  • Moonlight at 6 = ['1', 'b3', '3', '5', '6', 'b7'] (6-z50) [Bluesy Dominant]
  • Bridge at b7 = ['1', 'b2', '3', '4', '5', 'b7'] (6-z29) [Dominant 7]
  • Bridge at b2 = ['1', 'b2', 'b3', '3', '5', 'b6', 'b7'] (7-32B) [Altered Dominant]
  • Bridge at 5 = ['1', 'b2', '2', '3', '5', '6', 'b7'] (7-25B) [Dominant]
• Major / Dominant
  • Moonlight at 3 = ['1', '2', '3', '4', '5', 'b7', '7'] (7-29A) [Major / Dominant]
  • Moonlight at b7 = ['1', 'b2', '3', '4', 'b6', 'b7', '7'] (7-z18B) [Major / Dominant]
  • Bridge at 3 = ['1', 'b2', '3', 'b5', '5', 'b7', '7'] (7-19B) [Major / Dominant]
• Suspended / Exotic
  • Moonlight at 4 = ['1', 'b3', '4', 'b5', 'b6', '7'] (6-z50) [Diminished Maj 7]
  • Moonlight at 7 = ['1', '2', '4', 'b5', '6', '7'] (6-z50) [Suspended]
  • Moonlight at 5 = ['1', 'b2', '2', '4', '5', 'b6', 'b7'] (7-29B) [Ratnangi]
  • Moonlight at b6 = ['1', '2', 'b3', 'b5', 'b6', '6', '7'] (7-31B) [Diminished Maj 7]
  • Bridge at 4 = ['1', '2', '4', '5', 'b6', '7'] (6-z29) [Suspended / Major 7]
  • Bridge at 7 = ['1', 'b2', '2', '4', 'b5', 'b6', '7'] (7-19A) [Suspended]

Some Observations

The Photic Zone

Moonlight follows the logic of Expanded Lydian if you play it up or down a semitone on a major seventh sound. It's more dissonant and angular than Expanded Lydian, I think, but that might be just because I'm not familiar with it yet.

Similarly, Bridge follows the logic of minor up a minor third, even down to going down a minor third creating a kind of "relative major" sound. This and the previous example cast Bridge and Moonlight in the role of altered versions of the common minor pentatonic scale.

Both Moonlight and Bridge can go up a major third and function on a major 7 sound. The pattern of the Coltrane Cycle doesn't apply though -- the versions at the root or #5 contain the "wrong" notes and produce something much more dissonant.

The Mesopelagic Zone

All this is well and good but you know where the real action lies -- not with the sharks and dolphins we've just looked at but the weird abyssal things at the bottom of the list, the "suspended and exotic" section.

They split into two categories. One is the pair of Moonlights at the 4 and b6, two versions of the diminished major 7 sound; this is the twilight zone of the deep sea where sunlight still just barely penetrates.

This sound is part of octatonic diminished language and was a favourite of composers like Debussy and Ravel. These are often touted as jazz chords -- I don't know how much evidence there is for this on recordings but here's a video of somebody demonstrating the sound and some applications that certainly sound jazzy:

The Abyss

We arrive at the bottom of the list, the Bridges and Moonlights that don't fit with any tonal logic at all. This is where the real oddities might be found: sounds like these are why we set out on such an eccentric journey in the first place.

At this point I'm not so interested in the actual notes as how these relate to each other. We have:

• Moonlight at 7 (6-z50, 1-2-4-b5-6-7), a mode whose complement is Bridge at b2 (Dominant, mode of Sarasangi). This would be diatonic if not for the 4 and b5 appearing together with the 7; it's a kind of "diminished Maj 7 suspended" idea.
• Moonlight at 5 (7-29B, Ratnangi, 1-b2-2-4-5-b6-b7), a hypermode whose complement (minus the root) is Bridge at 6 (Major 7). Again there's an almost-diatonic quality to this: it's like you're playing Natural Minor and Phrygian at the same time but without the minor third.
• Bridge at 4 (6-z29, 1-2-4-5-b6-7), a mode whose complement is Moonlight at b3 (Dominant, mode of Neetimati). This one is just Harmonic Minor without the third.
• Bridge at 7 (7-19A, 1-b2-2-4-b5-b6-7), a hypermode whose complement (minus the root) is Moonlight at 6 (Dominant). It's Locrian with the natural 2 instead of the b3.

So although these are very exotic on paper, they're maybe not as far removed from familiar things as might first appear. They're not wildly dissonant and can make rather plain-speaking melodies, especially the six-note versions.

That's partly because there are only 12 notes in the octave and if we pick 6 or 7 of them we're going to get something with familiar elements in it. It's also because suspended sounds actually aren't all that unfamiliar -- for example, we heard them a lot when people play modes of the common pentatonic. I would think of these as spicier versions of the same general idea. They're potentially rather gentle on the ear but still ambiguous enough that they don't imply any particular tonal harmony.

Here are CAGED fingerings for all these.

Moonlight at 7 (6-z50, a mode of Moonlight):

Moonlight at 5 (7-29B, Ratnangi):

Bridge at 4 (6-z29, a mode of Bridge):

Bridge at 7 (7-19A, a mode of Gavambhodi/Hatakambari):