Naming of diminished chords

Subject: Naming of diminished chords
From: Gary T
Date: 26 Aug 02 - 01:30 AM

So I check out a piece of sheet music, song in key of C, and it has a chord labeled "F#dim." Since this chord can also be called "Cdim," why do they label it F#? Sure, it's got an F# note in it no matter what you call it, but it seems to me it would make more sense to call it Cdim when you're actually in the key of C.

I'm aware that each of the three diminished (diminished 7th?) chords can be named after any of the four notes that comprise it. Is there some convention or aspect of music theory that dictates which note is used for the name? Or is it just arbitrary personal preference that applies? Anyone know?

Subject: RE: Naming of diminished chords
From: GUEST,Boromir
Date: 26 Aug 02 - 09:41 AM

What chord precedes it and what chord follows it. F# diminished is the 'leading tone' to G.

Subject: RE: Naming of diminished chords
From: SharonA
Date: 26 Aug 02 - 09:44 AM

Good question. There's a little bit about the subject here – http://www.dolmetsch.com/musictheory31.htm#dimsevenths – but no rule about what the chord should be named in any of the situations described there.

I'm also seeing, on other music-theory sites, the mention of half-diminished chords and diminished-fifth chords, without a satisfactory definition of either. Can anyone shed any light on the subject of these two terms?

Subject: RE: Naming of diminished chords
From: GUEST
Date: 26 Aug 02 - 09:56 AM

A diminished 5th is the same as a diminished chord (B D F) without a seventh. Your link points out that it often is substituted for a dominant 7th and resolves to the tonic of the key. BDF, when played with a G in the bass, becomes a G7.

The root of a diminished chord generally leads to the root of the chord following it. So, a B diminished would resolve to a C. A D diminished would lead to an Eb and an F diminished would lead to an F#.

Diminished chords occur naturally on the seventh step of a diatonic scale (ti). The seventh step of a scale is also called the leading tone because it so desparately wants to go back home to the tonic. Sing "Shave and a Haircut" and stop on the two before bits and see if what happens.

Subject: RE: Naming of diminished chords
From: Gary T
Date: 26 Aug 02 - 09:57 AM

Boromir, in this case it goes F-F#dim-C.

Subject: RE: Naming of diminished chords
From: GUEST,boromir
Date: 26 Aug 02 - 10:15 AM

A C with a G in the bass?

Subject: RE: Naming of diminished chords
From: SharonA
Date: 26 Aug 02 - 11:50 AM

Thanks, Guest. Re "two bits": I remember a story about one of the classical composers (I forget which one): his children used to tease him by sneaking through the house in the middle of the night and playing a 7th chord on the piano, then waiting for Dad to get out of bed to play the tonic chord!

Still wondering what a half-diminished chord is. Anybody know?

Subject: RE: Naming of diminished chords
From: Pene Azul
Date: 26 Aug 02 - 12:00 PM

A half-diminished 7th chord is a diminished 7th chord with the 7th a half-step higher (interval of minor 7th), a minor-seventh chord with a flatted fifth. It's the chord built on vii in a major key. For example, Bmin7b5: BDFA (built on the vii of C major).

Jeff

Subject: RE: Naming of diminished chords
From: Don Firth
Date: 26 Aug 02 - 01:24 PM

Since C is your tonic chord, you probably wouldn't want to usurp it's position by converting it to a C dim 7th. According to conventional voice leading (the structure of the following chord), it would have nowhere to go that would make any kind of sense in the key of C—unless you wanted to modulate to another key.

Following the conventions for building diminished 7th chords and "spelling" them correctly, i.e., a pile of minor 3rds, or Root, minor 3rd, diminished 5th, and diminished 7th, here are various spellings of the same chord:

F# – A – C – Eb
A – C – Eb- Gb
C – Eb – Gb – Bbb
Eb – Gb – Bbb – Dbb

Insane, no?

In a sense, though, relative to the keys that they're in, they are not the same chord. It depends on the chord's function within the key. A diminished 7th chord needs to be resolved. One of the notes must function as a leading tone, that is, it must resolve to the root note of the major or minor chord that follows it (not necessarily the tonic). So that gives a clue as to how the chord needs to be spelled. What's the next chord?

I agree with Boromir. I see it as resolving to a G. The way the F# dim 7th relates to the key of C, resolving to any other chord (Bb, Db, or Fbb) strikes me as kind of goofy. A possible exception might be the Bb, which is the subdominant chord of the subdominant key (F), which means you've modulated. Slightly weird.

Don Firth

Subject: RE: Naming of diminished chords
From: allanwill
Date: 26 Aug 02 - 01:43 PM

Holy snapping dragons, I need a headache pill!

Allan

Subject: RE: Naming of diminished chords
From: Cappuccino
Date: 26 Aug 02 - 04:08 PM

I was once in a band where we always referred to them as 'demented' chords.

I still think of them that way...

- Ian B

Subject: RE: Naming of diminished chords
From: M.Ted
Date: 26 Aug 02 - 05:35 PM

Gary,

Diminished chords often reflect a chromatic movement in the chordal structure of a tune(which means that,in effect,the key changes from one beat to the next) so when your chords go from C to Cdim to G7, you really have a voice that moves down by half steps: G-F#-F--the arranger may name the chord to emphasize that movement--on the other hand, it might have just been an arbitrary choice, since the chord symbols are usually just an after-thought for them-

Subject: RE: Naming of diminished chords
From: fogie
Date: 27 Aug 02 - 04:15 AM

Still as clear as mud to me, always confused about dims.

Subject: RE: Naming of diminished chords
From: Don Firth
Date: 27 Aug 02 - 08:50 PM

About chords in song books and sheet music:— Don't take them as necessarily authoritative. I've seen chord symbols in folk song collections that were fairly obviously worked out by jazz guitarists moonlighting for some music publishing company, who obviously knew nothing about folk songs. These "arrangements" were full of 6th, 9th, 11th, augmented, and diminished chords, completely inappropriate for the songs, and splattered all over the page; so much so that it was sometimes hard to pick out the basic I, IV, V harmonic structure by looking at the chords. Also, look out for song books that have both piano accompaniments and guitar chords. These are often done by formally trained musicians (sometimes the piano arranger himself or herself) who may know nothing about the guitar, but who tries to translate the piano arrangement into guitar chords. And if the song happens to be in Dorian or Mixolydian mode as a number of folk songs are, the result can be a real goat's breakfast. The chords in some song books you can trust, but always approach them with a twenty-pound grain of salt and be prepared to work out your own.

Don Firth

Subject: RE: Naming of diminished chords
From: M.Ted
Date: 28 Aug 02 - 01:06 AM

Most important point, Don!--then of course, there are the folksongs written out in the key of Eb and Ab--It's no wonder that so many folk musicians never bother to learn to read music--

Subject: RE: Naming of diminished chords
From: Mark Cohen
Date: 28 Aug 02 - 02:24 AM

Goat's breakfast? That's a new one on me, Don...but it's perfect!

I agree with Don that trying to follow chords in a songbook can be frustrating, because the editor will frequently just look at whatever combination of notes happens to be in the left hand part at that point in the measure, and give it a name that may have very little to do with the actual chord structure of the song. Good arrangements, after all, are not just a series of I-IV-V static chords, but are composed of moving and interweaving voices. The chord names are an imperfect snapshot of what the accompaniment is actually doing. Unless you're talking something like Kumbaya, of course...

Aloha,
Mark

Subject: RE: Naming of diminished chords
From: Pied Piper
Date: 28 Aug 02 - 06:23 AM

Today we have naming of chords

Subject: RE: Naming of diminished chords
From: M.Ted
Date: 28 Aug 02 - 08:49 AM

Mark,

I have actually engaged in discussions with arrangers who make up the sloppy chords that you see on sheet music, and they are completely clueless--They make no distinction between the sort of chords you'd need for "Stardust" and the chords you'd need for "Blowin'in the Wind"--

Subject: RE: Naming of diminished chords
From: pattyClink
Date: 28 Aug 02 - 09:23 AM

Just a thanks to all those who contributed info on this thread. I'm learning vocal arranging and have found these 'symmetrical' chords baffling also. Appreciate the 'why' answers as well as the straight facts, it helps one understand.

The Ab and Eb keys are indeed used a lot, that is a problem. I know it's because they are comfortable keys for voices to sing in, but I don't get it either. Seems like we could all write in a few standard keys and shift pitch a few half-steps when necessary.

Subject: RE: Naming of diminished chords
From: Rick Fielding
Date: 28 Aug 02 - 09:54 AM

I LOVE these threads (naturally), especially when the info is correct!

But I'm gonna aim my two cents worth at the folks who are totally discombobulated at the technical aspects of all this stuff.

Here's a totally simple way to HEAR how the diminished (and diminished seventh) chord works, and what it can do for your music:

Just strum these changes using a bass note first and then a chord.

E (pick E bass and then strum rest of chord)

A7 (pick A bass and then strum rest of chord...play two finger A7 and use middle and ring fingers)

KEEP the A7th chord, but place index finger on fifth string, first fret. Pick A# bass (fifth string) and strum rest of chord.

Finish off by playing E again, but this time pick B note first (fifth string second fret)

Rick

Subject: RE: Naming of diminished chords
From: M.Ted
Date: 28 Aug 02 - 01:56 PM

The secret behind this bit of deft Fielding prestidigitation is simple:

Take any seventh chord(just grabbing one out of the air, lets say, A7: A-C#-E-G) and raise the fundamental (A, in this case) and you have a diminished chord: A#-C#-E-G--

The backward trick is even more amazing:

Lower any note in a diminished chord by one half step, and you have a major seventh chord of the same name:

A-C#-E-G is A7
A#(Bb)-C-E-G is C7
A#(Bb)-C#(Db)-Eb-G is Eb7th
A#-C#-E-Gb(F#) is Gb7 and F#7

Subject: RE: Naming of diminished chords
From: Gary T
Date: 28 Aug 02 - 02:21 PM

Thanks to all for the input.

A little more info--there are two songs I've been working on recently, "Hey There" and "Chattanooga Choo Choo." I have sheet music for both, and it seems to me that the chord sequences are essentially correct. (They are rather "busy" sequences, and "Choo Choo" in particular has a number of chords that I've simplified or dispensed with, but the portions with the diminished chords strike me as right on.)

One of these songs has a passage that goes F-F#dim-C, the other one has a passage that goes F-Cdim-C. It just struck me as odd to use the "F#" nomenclature in the key of C, which virtually never has F# chords, especially when the "C" nomenclature is available to name what is for all intents and purposes (as far as I know) the same chord.

On a side note, related to M. Ted's observation above on 7th chords, I've noticed that this Cdim chord can sometimes substitute for, or be substituted by, a D7 or B7. In either case, 3 of the 4 notes are the same, and in certain situations the one chord sounds about as right as the other. A handy little trick to have up one's sleeve.

Subject: RE: Naming of diminished chords
From: Don Firth
Date: 28 Aug 02 - 02:24 PM

Now THAT's the way to use diminished 7ths!! And you don't even have to think in terms of diminished 7ths because you're using them as passing chords (or standard, off-the-shelf chords with a passing tone added).

Don Firth

Subject: RE: Naming of diminished chords
From: M.Ted
Date: 28 Aug 02 - 03:27 PM

The passages you are looking should probably be played F/F#°/Gm7/C9, though, in checking my charts, I am not sure quite what parts of the tunes you are talking about--anyway, in that kind of chord progression, the bass line is moving chromatically(by half-steps) and the F# is not in the key--it is written as an accidental--jazz melodies don't quite follow the rules of diatonic melodies, because, as the chords move through the circle of 4ths, so does the key of the melody--in other words, those accidentals really mean that you are playing in another key than the one you started in.

Subject: RE: Naming of diminished chords
From: GUEST,MCP
Date: 28 Aug 02 - 04:03 PM

GaryT

In relation to using the Cdim7 as a substitute for D7 and B7, you should note that the dim7chors is the same as a dominant 7th chord with a flattened 9th (7b9 chord) with the root omitted.

  So Cdim7 = C Eb Gb A
  
  and:
  
  B7b9   = B D# F# A C     or B  [Eb Gb A C]
  D7b9   = D F# A C Eb     or D  [Gb A C Eb]
  Ab7b9  = Ab C Eb Gb Bbb  or Ab [C Eb Gb A]
  F7b9   = F A C Eb Gb     or F  [A C Eb Gb]
  
  In each case you have the Cdim7 chord over the root of the 7b9 chord. Leaving out the root leaves you the Cdim7 chord, which is why it can substitute for these dominant type chords.
  
  Mick   




	

Subject: RE: Naming of diminished chords
From: GUEST
Date: 27 Aug 13 - 01:05 AM

In the Key of C the F#dim chord is a #IV that leads to the V chord and is commonly known as the "gospel diminished chord" because it shows up so frequently in that position. Check out Ray Charles progressions for example.

Subject: RE: Naming of diminished chords
From: GUEST,Grishka
Date: 27 Aug 13 - 04:21 AM

Whenever the theory of "leading" applies, the chord should be named according to the leading note, as elaborated above. The spelling of the accidentals will then reflect towering thirds: Cdim7 would be C-Eb-Gb-Bbb, correctly leading to Db major.

However, these chords have many other functions. The progression Cdim7 → C is very common, and the natural spelling of that Cdim7 would be C-D#-F#-A. To make this into towering thirds, we must start with D#, so that the "correct" name would be D#dim7, but it does not lead to E major, not even "implied", "elided", "subsidiary", or "replaced".

In such situations, I find the chord is best named according to its bass note. Chord symbols are very rough approximations of the actual harmonic content, only good for practical purposes, even in cases like Kumbayah.

Subject: RE: Naming of diminished chords
From: doc.tom
Date: 27 Aug 13 - 04:22 AM

Excellent! Lots of good info. Now let's start on the augmented chords!.....

Subject: RE: Naming of diminished chords
From: GUEST,Grishka
Date: 27 Aug 13 - 09:38 AM

If an augmented chord works as a substitute for the dominant of a minor chord, name it accordingly: E+5 → Am. This also applies if the minor chord is merely implied, or substituted (e.g. by A major in this case).

In all other cases I tend to adopt the bass tone rule, but that is just my personal preference. One of my mantras at Mudcat is to have an eye on the bass line.

Subject: RE: Naming of diminished chords
From: Artful Codger
Date: 27 Aug 13 - 11:40 AM

Re the Cdim7 to C progression:
Note that C is enharmonically equivalent to B#, where the succeeding dim7 thirds are indeed D#-F#-A. So if you wanted to be pedantic, you could write B#dim7 instead of Cdim7. Then B# would "lead" to its enharmonic equivalent C (root), D# to E (third) and F# to G (fifth); you could even say A leads down to G. But however "correct" this would be in reflecting theory, virtually every fretted instrument player would simply chart this as Cdim7.

If I have doubts, I name a dim7 chord according to the nearest chord (usually a dom 7) that would be my second choice. The root is either identical or a semitone off, and the harmonic function is very similar.

Subject: RE: Naming of diminished chords
From: GUEST,Grishka
Date: 27 Aug 13 - 01:03 PM

Quite funny, Artful, but before anyone takes it seriously, let us note that if B# leads anywhere, then to C#.

Long ago I read a book in which than Cdim7 was described as of "subdominant type", because of the C and the A. This would favour the naming F#dim7, were it not for that note that moves to E and should thus be spelled D#.

I often find myself writing, say, Eb in one voice and D# in another one, both appearing perfectly justified in their melodic context, the harmonies not being any more exotic than, say, Wagner's.

The Devil and His Grandmother in music. To Hell with theories that neither fit the problem nor benefit us.

Subject: RE: Naming of diminished chords
From: Artful Codger
Date: 27 Aug 13 - 09:19 PM

What is "funny" is your arbitrary rule that the root of a dim7 chord MUST lead. This happens frequently, but isn't the only scenario. Cdim7 can resolve to C in the way that Cm7 can resolve to C. This relationship is even stronger between Cdim7 and C6, where the only differences are the two interior leading notes (as one might slur melody notes). The sound is similar to a chromatic slide: B6 to C6--note the similarity to my "funny" B#dim7 explanation. Omit the "coloring" 7th and the relationship is even more apparent. You can consider the progression either as a change in quality with static root or as a "leading" slide with modified root.

Dim7 by its nature is tonally ambiguous, allowing it to resolve (or merely move) to a variety of targets. This is greatly aided by equal temperament which minimizes the disparity and fixity of enharmonic equivalents in the harmonic context, so that one pitch can be perceived as simultaneously behaving and sounding like Eb and D#. The theory becomes more complex, with one chord suggesting different roles simultaneously, but the chord naming isn't completely arbitrary, as in your "lowest note" naming scheme.

Subject: RE: Naming of diminished chords
From: GUEST,Grishka
Date: 28 Aug 13 - 05:38 AM

I thought you meant it funny - my apologies if you did not. As for the "your arbitrary rule that the root of a dim7 chord MUST lead", if you were addressing me personally, I wrote the very contrary.

My bass note naming scheme is indeed not reflecting any harmonic role. In cases where such a role is clearly visible, it should take precedence. In all other cases any rule will do. Mine has the advantage of easy readability, not requiring a slash for the bass note.

The applicability of "functional harmonics" diminishes continuously, starting about 1800 and not quite ending with Stravinsky (as suggested in the other thread currently active). Whenever it fails to explain something in a way that benefits the musicians, these should not be bothered with it at all. Note that other theories, "non-functional", have been suggested, e.g. by Paul Hindemith, principally targeted at composers. Those who read those books at all rarely found them of use for their own work.

Jazz theory may be an exception, but has also often been criticized. For the question of the thread title, its most common answer is "all are equivalent". Since the authors define the chord by towering thirds, it makes sense to use a name for which this does not imply any double accidentals, but I would not worry too much about that. Jazz and orthography are separate worlds anyway.

Subject: RE: Naming of diminished chords
From: Stringsinger
Date: 28 Aug 13 - 06:49 PM

The diminished chord takes its name from the chord for which it substitutes.
It is the third of the dominant seventh flat nine chord and when that third is called
the "root" , than the original root of the dominant seventh flat nine is called the generator.

In a diminished seventh, their are four practical and eight possible roots.

As to the first point, an example: The A7b9 chord has C# as the third.
Building the top four notes of the A7b9 will give you C#-E-G-Bb.
This spells out a C# diminished seventh chord with A as the generator.

In practical usage, though, if you see a diminished seventh chord, it is generally
named for the bass motion of the root or if close to a tonic chord it will
either take it's name from the tonic tone or a step higher. Example,
Key of A, A diminished seventh or A# diminished seventh.

If this sounds complicated it's because it is but it can be shown by playing
examples.