m7b5 or Diminished?

**bobsguitars09** · 09-07-2009, 07:22 PM

m7b5 or Diminished? what is the difference?

**bako** · 09-07-2009, 07:35 PM

They differ by one note a half step away.
Cdim---------C Eb Gb Bbb--------1 b3 b5 bb7
Cm7b5-------C Eb Gb Bb---------1 b3 b5 b7

Diminished could possibly refer to the triad but generally refers to the seventh chord.

**bobsguitars09** · 09-07-2009, 07:39 PM

Thanks. I was confusing a half dim with a dim.

Half Diminished is the same as a m7b5 right?

**bako** · 09-07-2009, 07:49 PM

Yes

Same notes arrived at from 2 different angles.

Cm7------C Eb G Bb becomes
Cm7b5---C Eb Gb Bb

Cdim------C Eb Gb Bbb becomes
Chalf dim-C Eb Gb Bb

**bobsguitars09** · 09-07-2009, 08:18 PM

when a chart says Cdim it means Cdim7 right?

**bako** · 09-07-2009, 09:14 PM

when a chart says Cdim it means Cdim7 right?

Most of the time yes.
Unfortunately the triad is indicated the same way.

**bobsguitars09** · 09-07-2009, 09:32 PM

Dim Triad is 1 b3 b5?

**JohnW400** · 09-07-2009, 09:47 PM

Not usually. In most charts I've seen you play dim7.

EXCEPT !!

The notable difference is in tunes like Corcovado where the melody is E natural against an F diminished. Here the voicing is more of a diminshed /ma7. You see this chord a lot. It's also an E/F ( F Ab Cb E which enharmonically is F G# B E). This chord is also in Triste by Jobim and Letter to Evan by Bill evans.

I'm sure there are tons of other examples, I just can't recall them righ tnow

**Luan** · 09-08-2009, 01:44 PM

That major 7th in the dim7 chord is just a note from the scale I think, rather than a chord tone.

**randalljazz** · 09-08-2009, 02:11 PM

at least several authors consider the diminished major 7th to be a chord in its own right. it functions somewhat differently than plain dim 7th. sometimes written as a slash chord:

B/C for a C dim maj 7.

**JohnW400** · 09-08-2009, 02:15 PM

Originally Posted by Luan

That major 7th in the dim7 chord is just a note from the scale I think, rather than a chord tone.

It's a dimished triad with a major seventh interval. I never called it that until I was nosing around the AAJ site and saw it it named that way by several musicians there. It made perfect sense to me and reaffirmed that you can learn something new everyday.

**Luan** · 09-08-2009, 02:15 PM

actually you can use tensions for dim7 chords, any tension that is a whole step over a chord tone, 9th, 11th, b13th, and major 7th.

**Luan** · 09-08-2009, 02:16 PM

Oh i see you guys refer to a triad without the diminished 7th interval, now I get it.

**JohnW400** · 09-08-2009, 03:03 PM

I'm pretty sure Bill Evans used it in Letter to Evan as an Eb dim/G (I think) so the voicing comes out as:

G Eb Gb Bbb D. Almost like a full polychord D over Eb. I'll check the score later to confirm. But it's a nice sound. Very Jobim sounding

I'm with you Luan, the 9,11 etc added to a full dim7 sound great.

**chancho** · 10-13-2012, 01:00 PM

Im a beginner guitar lover and have been taking classes for under a year (very little progress btw). So i learned about progression recently, maj, min, min, maj, maj, min dim. But in trying to write (and eventually play) a progression I try writing down the progression only to find myself stuck when it comes to the last chord of the progression. Is it diminished or half-diminished? and what's the different formula between the two?

**woyvel** · 10-13-2012, 04:39 PM

So a full diminished can also be seen (and heard) as a m6b5?

**BigDaddyLoveHandles** · 10-13-2012, 04:47 PM

Originally Posted by woyvel

So a full diminished can also be seen (and heard) as a m6b5?

Yes, that would be enharmonic. When writing down the actual chord (not just the chord name), people often take a free hand with enharmonic notes.

**JonR** · 10-13-2012, 06:53 PM

Originally Posted by woyvel

So a full diminished can also be seen (and heard) as a m6b5?

If you spell it wrong, yes

.
It usually doesn't matter if you call the bb7 a 6, but the derivation is from vii degree of harmonic minor.
Eg, Bdim (B D F Ab) comes from C harmonic minor, so the Ab should not be called G#. (B-Ab is a 7th interval, not a 6th.)
But it does sound identical to B D F G#, which is G#dim7 from A harmonic minor

. (G#-F = dim 7th.)
Not to mention Ddim7 (D F Ab Cb) from Eb harmonic minor and E#dim7 (E# G# B F) from F# harmonic minor

.

And because dim7s are used freely in contexts outside of their harmonic minor origins, the enharmonics are (literally!) academic.

**BigDaddyLoveHandles** · 10-13-2012, 06:57 PM

I've mentioned this before, but I'd love to be in a situation where I'd have to write a Cb diminished 7th chord: Cb Ebb Gbb Bbbb. Yes my little friends, your eyes are not lying, that's a triple flat!

**cosmic gumbo** · 10-13-2012, 10:00 PM

Originally Posted by chancho

So i learned about progression recently, maj, min, min, maj, maj, min dim. Is it diminished or half=diminished? and what's the different formula between the two?

It looks like you are mentioning triads, so that would be a diminished triad, not a diminished7, or a half diminished.

When we get to stacking another 3rd on these triads they will become either a major7, minor7, dominant7, and minor7b5 (half diminished)

**bako** · 10-13-2012, 10:31 PM

Correct spelling of diminished chords is always in 3rds.
The world is not always correct.
Spelling and naming of diminished chords are correct only some of the time.

4 different diminished chords with the same notes enharmonically
root of each chord written in bold.

B D F Ab

D F Ab Cb

F Ab Cb Ebb

G# B D F

**JonR** · 10-14-2012, 06:22 AM

Originally Posted by bako

Correct spelling of diminished chords is always in 3rds.
The world is not always correct.
Spelling and naming of diminished chords are correct only some of the time.

4 different diminished chords with the same notes enharmonically
root of each chord written in bold.

B D F Ab

D F Ab Cb

F Ab Cb Ebb

G# B D F

Right - except, if we're being strict about derivation, Fdim7 would be more commonly written as E#dim7, from F# minor: E# G# B D.

And seeing as Eb minor and D# minor have the same number of flats/sharps in their key sig - so ought to be as common as each other - arguably Cxdim7 (Cx E# G# B, from D# minor) might theoretically be as common as Ddim7.

Naturally this all means there are only 3 different dim7 chords, in terms of sound. It's just that each of them can have (at least) 4 different names.

**bako** · 10-14-2012, 08:01 AM

Thanks Jon, derivation/context the other element in correct naming.

As a resolving diminished Fdim derive from Gb Minor as a I chord which is the relative of Bbb Major (9 flats).
Well liked musicians share the common trait of stopping at 7 flats or sharps for major keys.
Fdim would be correct resolving to Gb as a I chord in Gb Major, a IV chord in Db Major, a V chord in Cb Major among other places.

All this said, Fdim is seen more frequently than E#dim due to the social avoidance of E#, B#, Fb, Cb.

**fumblefingers** · 10-14-2012, 10:54 AM

what cosmic said.

in other words, you have simply listed the triads of a harmonized major scale. you should next harmonize 7th chords of the major scale, and understand their naming and intervallic make-up.

after that, do the same for minor, harmonic minor, melodic minor.

**griphon ii** · 10-14-2012, 04:48 PM

half and/or diminished is a dominant chord or a diminished in usage. In other words, it will go to a place of rest or another place of movement. Music moves most of the time. Please no jokes. I can, hardly, remember one chord tunes and don't want to, even though, they weren't really bad. The actual difference between the half and full diminished is the 9th or the b9 of the real dominant chord or change. Moving both half and full diminished in m3, minor 3rds, gives very interesting results. Actually, moving any change in m3 or M3 will provide interesting results. Take time to understand harmony. Most of the time, dominant or I depending on usage.