Diminished Triad and the b5

[tango_grass]

"So, Diminished chords = 1, b3, b5.

So if you flatten(diminish) the perfect 5th into a b(flat)5 to create the Dim Triad, why isn't it called a Flatted Chord/triad?"


A friend of mine posed me this question, and although I cannot get the point across, I feel it can be done! Maybe some of you have a great explanation of the laws of Diminished chords?

[Shelby Eicher]

Because calling it that doesn't accurately describe what going on. You have to account for the flatted 3rd. These chords are called half diminished or minor b5 chords. The minor b5 chord usually has a dominate 7th as well. Other chords that involve the flatted 5 tone as the 7#11(flatted 5 and sharp 11 being the same tone) is an entirely different chord because it's major and has a 7th. I hope this helps.
Shelby

[ManlyMandolinist]

Rameau knew what he was doing. You can thank him (or not) for chord theory.

http://www.amazon.com/Treatise-Harmo.../dp/0486224619

But more practically, when you get into diminished chords with a 7th added, you have two types: half and fully diminished. The former is a diminished triad w/ a minor 7th from the root added. The latter is diminished triad w/ a diminished seventh added.

You could call those "flatted chords" or "half flatted" chords, but you could also call the sky green. Everything's arbitrary. Go with what allows you to communicate effectively with other musicians. Most musicians use the term "diminished triad."

[Don Stiernberg]

Remember that to diminish means to flat or lower by one half step, just as to augment means to sharp or raise by one half step. Symbols for these activities are minus(to lower) and +(to raise).
The circle you see for a full diminished chord indicates that all possible intervals have been lowered, as Shelby explained. A chord with a flatted third, flatted fifth, and DOUBLE flatted seventh is a full diminished chord, for instance G-Bb-Db-E=G diminished. A half-diminished chord, (a/k/a m7b5)does not double-flat the seventh. So G-Bb-Db-F=Gm7b5 or G half-diminished. Perhaps the distinctions come from starting with a four note chord instead of a triad:
1-3-5-b7=dominant chord, say, G7
1-b3-5-b7=m7 chord, say, Gm7
1-b3-b5-b7=m7b5 chord, G half-diminished
1-b3-b5-bb7=diminished chord. G-Bb-Db-E=G diminished
Diminished chord theory is easier to hear, or see on the fretboard, than to grasp or explain. Even more as the improvising scales are dealt with! I hope Groveland, Eschliman,and McGann(theory cats, not a law firm!) wiegh in too, because the more attempts we all make to get to the bottom of this the closer we'll get to a true understanding of it. Better yet we'll get closer to being able to play all those cool connecting licks like Mark O'Connor does or Benny Thomason, or Django or George Benson or Jethro or Tiny...

[Jim Broyles]

...or Donnie.

[tango_grass]

My friend will pose me with many more headaches with all the posed explanations....Thanks guys! :D

[Nolan]

I had to print off a piano keyboard to follow along!

I've always thought of diminished chords as stacked minor thirds (1.5 steps between the notes) while augmented chords were stacked major thirds (2 full steps). Seems easier (at least to me) to understand when put in those terms.

[mandroid]

Looking at my piano for dummys wall chart
the I/1, b3rd , b7th is a diminished triad such as C bE bG .

key of B which is written with 5#s is diminished with B,D and F natural notes, rather than
B,D#,F#, which the Major triad would use

so its a triad with 3 notes, add the 7th and thats four notes then its not a triad anymore .

U can call either a chord though, being More than 2 notes.

[bobby bill]

With regard to why it is called a diminished chord rather than a flatted chord, I would say the latter could get ambiguous and maybe confusing. "Flatted fifth" implies a fifth that has been lowered by way of an accidental. "Diminished fifth" simply refers to an interval that may or may not be in the key signature.

For example, in the key of C, the vii chord (b d f) is diminished (I don't know how to make a little circle after the vii or I would have). None of the notes is flatted, but the fifth is certainly diminished. To call it a vii flatted chord doesn't make sense since nothing is flatted and someone might think you were referring to a Flat VII chord (B flat, D, F).

The bottom line, of course, is that the reason we call it a diminished chord instead of a flatted chord is that that is what everyone else calls it.

[Jim Broyles]

In Windows, a little circle is: Alt + 0176. See? ° Can't help you for Mac.

[Walter Newton]

In Windows, a little circle is: Alt + 0176. See? ° Can't help you for Mac.

On a Mac º is Option + 0 (the number zero, not the letter O - which gives ø, a symbol some use for "half diminished")

[Doug Hoople]

My friend will pose me with many more headaches with all the posed explanations....Thanks guys! :D

Actually, your friend is onto something...

When paired with a dominant 7th, it IS called the minor7-flat5 chord, also known as the half-diminished chord.

So there's at least one variant that sort of fits in the category your friend is suggesting!

[ManlyMandolinist]

With regard to why it is called a diminished chord rather than a flatted chord, I would say the latter could get ambiguous and maybe confusing. "Flatted fifth" implies a fifth that has been lowered by way of an accidental. "Diminished fifth" simply refers to an interval that may or may not be in the key signature.

solid point

[Evan Mahoney]

"G-Bb-Db-E=G diminished"

Actually, Mr. S, you are partially incorrect. The above spelling is in fact not the spelling of a G Dim chord. The spelling you have listed is closer to a German 6 in the key of Bb. While E and Fb are enharmonically equivalent, the spelling is important because E is the 6th of G while F is the 7th; when the function of the chord is determined by the spelling, correct spellings are important. I'm pretty sure no one wants a Facebook club on Chromatic Modulation with altered 6's, so if you are not a fan of the double-flat. (I am) choose a different chord to make your case. Take care.

[Jim Dalton]

"G-Bb-Db-E=G diminished"

Actually, Mr. S, you are partially incorrect. The above spelling is in fact not the spelling of a G Dim chord. The spelling you have listed is closer to a German 6 in the key of Bb. While E and Fb are enharmonically equivalent, the spelling is important because E is the 6th of G while F is the 7th; when the function of the chord is determined by the spelling, correct spellings are important. I'm pretty sure no one wants a Facebook club on Chromatic Modulation with altered 6's, so if you are not a fan of the double-flat. (I am) choose a different chord to make your case. Take care.

Well, you're not quite right either:

Yes, you do have the spelling of the diminished chord right but the German sixth chord in Bb is spelled Gb - Bb - Db - E.

[Mike Bunting]

[/QUOTE]Yes, you do have the spelling of the diminished chord right but the German sixth chord in Bb is spelled Gb - Bb - Db - E.[/QUOTE]

I'm not sure I follow this, where does the Gb come in, the sixth of Bb is G, no? Is it different in the German system?

[Jim Dalton]

removing duplicate

[Jim Dalton]

Yes, you do have the spelling of the diminished chord right but the German sixth chord in Bb is spelled Gb - Bb - Db - E.

I'm not sure I follow this, where does the Gb come in, the sixth of Bb is G, no? Is it different in the German system?

The German augmented sixth chord (abbreviated Ger+6) is a chromatic chord. Which means that some pitches are altered from their diatonic scale versions.

The augmented sixth intervals (in this case-- Gb to E) resolves outward to an octave on the dominant tone (F). In fact the function of the chord is to intensify motion toward the V chord or dominant.

The name "German" doesn't really indicate any national preference, it's just traditional. The same goes for the other augmented sixth chord names: Italian and French.

[Mike Bunting]

One more, is an augmented sixth different than what we call just a sixth, i.e. A6?

[Bruce Clausen]

For those of us used to chord symbols, the German sixth is more or less the first chord in the common cadence Gb7-F7-Bb. (That is, Gb7 gves the right sound but not the correct spelling.) The French sixth would be Gb7-5, or (more correctly spelled) C7-5. Italian sixth is like a dominant seventh with no fifth (but again with the spelling issue). For orchestrators and arrangers the spelling issue is an important one, as correct spelling gives each player's part a coherent melodic shape.

For the diminished chords, some (that is, I) prefer to distinguish clearly between the three-note diminished triad and the two four-note seventh chords:

E dim: E-G-Bb
E dim7: E-G-Bb-Db
E half-dim7 or Em7-5: E-G-Bb-D

(Mike: The A6 chord has the major sixth interval, A-F#. Augmented sixth would be a larger interval, e.g. A to F##, which *sounds* like A to G.)

--BC

[Mike Bunting]

Mike: The A6 chord has the major six... like A to G.)
Thanks, that accounts for my confusion.

[groveland]

Fascinating. Jim, Bruce, et.al. - Not everyone gets a chance to go here, so I have to take the opportunity. What I am about to ask may be confusing, so I won't be offended if everyone bails.

So the "German Sixth" is how we refer to the condition where the interval of the sixth is raised, and in the context the name should communicate that condition (sharp the name of the note that is the sixth).

In the Gb7 example, Gb Bb Db Fb are the notes of that chord, but it's in Bb, and Bb has no Fb, it has an E (enharmonic to the Fb). So in that context the interval in the Gb7 chord between the Gb and the Fb is called a "German Sixth" because it's really an E in Bb, and the interval between a Gb and an E is an augmented sixth?

Cool. (If I got that right.)

And the actual interval distance of an augmented 6th and a flatted 7th is identical. But they are technically not the same functionally, depending on the context.

Is that about right?

Thanks in advance, Jim, Bruce, et.al.

[Bruce Clausen]

Wow. Some mental gymnastics required here. Let's see. In classical music it's very common to delay the dominant chord using various other chords (especially the "I 6/4", the second inversion tonic chord), as a way of intensifying the suspense and the sense of direction. Further delay is achieved by delaying the 6/4 chord. (In jazz we put II-V, or III-VI-II-V, or #IV-VII-III-VI-II-V with the same basic goal.) A strong pull towards either the I 6/4 or the dominant chord itself can be achieved by using the "augmented sixth" chords, which (in a major key) involve two accidentals, one pulling down, the other up. For example (still in Bb): Gb-Bb-Db-E (the E nat. is an accidental in Bb major) leading to either F-Bb-D-F (I 6/4) or F-A-C-F (V). The "augmented sixth" is this interval Gb-E, and the three chords mentioned by Jim above are the standard forms in which it is used. Other chords also lead nicely to the dominant, e.g. Gb-Bb-Eb (IVm), or G-Bb-E (#IV dim.). The augmented sixth chords combine the chromaticism of both these.

(A little problem here is the Db resolving up to D in my example. For this situation, I seem to recall Piston actually writing C# and speaking of a "doubly augmented fourth chord": the inverval Gb-C# being in fact a doubly augmented fourth. I'm not sure we really need that concept.)

BC

[Jim Dalton]

Fascinating. Jim, Bruce, et.al. - Not everyone gets a chance to go here, so I have to take the opportunity. What I am about to ask may be confusing, so I won't be offended if everyone bails.

So the "German Sixth" is how we refer to the condition where the interval of the sixth is raised, and in the context the name should communicate that condition (sharp the name of the note that is the sixth).

In the Gb7 example, Gb Bb Db Fb are the notes of that chord, but it's in Bb, and Bb has no Fb, it has an E (enharmonic to the Fb). So in that context the interval in the Gb7 chord between the Gb and the Fb is called a "German Sixth" because it's really an E in Bb, and the interval between a Gb and an E is an augmented sixth?

Cool. (If I got that right.)

And the actual interval distance of an augmented 6th and a flatted 7th is identical. But they are technically not the same functionally, depending on the context.

Is that about right?

Thanks in advance, Jim, Bruce, et.al.

Yes, you have that right. In classical harmony, the seventh of a chord resolves down by step into the next chord. In the case of a Gb7, the Fb would resolve down to the third (Eb) of a Cb chord.

However, the augmented sixth interval has a tendency to resolve outward, a half step in each direction, to an octave on the dominant which would support either the dominant chord or I 6/4 (either F7 or second inversion Bb in the case of the chord above).

Bruce is right about the voice leading issues in his last paragraph.

The fact that the German chord sounds like a dominant seventh chord allows for some of the most interesting events in traditional harmony -- enharmonic modulations. This means that the "other meaning" of the chord (spelled differently) can be used to shift to remote keys -- almost like a harmonic pun.

--------------------------------------------

Just another note, I am one of those who sees the augmented sixth "chords" more as simultaneities or voice leading types than actual chords. Even if you think of them as chords, they really don't have a theoretical root that fits with the way we construct the other chords in the system.

[groveland]

Many thanks.

And I blew the dust off Piston (3rd ed.) - It's Chapter 24 if anyone's interested.