When to use half-diminished and diminished chords?

**Ashlee** · 10-18-2010, 10:06 AM

Hello everyone!

So I just discovered half-diminished (1-b3-b5-b7) and diminished chords (1-b3-b5-bb7).

They sound so strange when I play them by themselves, but I'm sure they sound great in the right context.

I was wondering if anyone could give me some suggestions on when to use them? I'm assuming they are passing chords, but when would I use them?

I appreciate any advice on this!

Thank you!

**derek** · 10-18-2010, 10:16 AM

Hi Ashley. The half diminished chord is the ii chord in a minor ii V I. Think of Autumn Leaves or Alone Together. Sounds great in that context. Diminished chords are often used as passing chords, to create movement. Those are the simplest uses of the two. They both also can function as dominant chords.

**Ashlee** · 10-18-2010, 10:18 AM

Thank you!

**rabbit** · 10-18-2010, 01:21 PM

Eb Maj7---E dim7---F min7---F# dim7....
x6878x x7868x x8689x x9-10-8-10x
a classic sequence, as I recently learned, the beginning of "Ain't Misbehavin',"
among others.

Best of luck.

**BigDaddyLoveHandles** · 10-18-2010, 02:13 PM

Another example: dim7 can stand in for a rootless 7b9. For example,

A7b9 = A C# E G Bb
Bbdim7 = Bb C# E G

Example use: Jobim's Wave starts with DMaj7 Bbdim7 Amin7 ... I think of that Bbdim7 functioning as a A7b9.

**Ashlee** · 10-18-2010, 03:35 PM

Thank you this is all very helpful! Can't wait to get home and try some of this stuff!

**timscarey** · 10-18-2010, 04:11 PM

Half dim can also be a tritone sub for the 1 chord.

BbMaj7 - EbMaj7- Dmin - G7 becomes
Emin7(b5)- EbMaj7- Dmin - G7

I think that happens in "I thought about you" and "on a misty night" It also happens in "ain't no mountain high enough" the first few chords are.

Bm7/A - Abmin7(b5) - GMaj7 - F#m7 - Em7 Repeat

I see this as.... Vsus - I- IV - iii - ii in the Key of D

the Ab chord being the tritone sub for 1

**BigDaddyLoveHandles** · 10-18-2010, 04:22 PM

Originally Posted by timscarey

Half dim can also be a tritone sub for the 1 chord.

BbMaj7 - EbMaj7- Dmin - G7 becomes
Emin7(b5)- EbMaj7- Dmin - G7

I like that. I usually only think about tritone subs over dominant chords, but that sounds nice, and #11s over major chords are cool.

**timscarey** · 10-18-2010, 05:10 PM

Fully Diminished chords can also sub for the 1 chord. Usually at the end of a phrase when the melody is on the tonic. I call it a "Tonic Diminished" it happens in a lot of Jobim stuff like "Chega De Saudade" and a lot of old show tunes...

Fm7---Bbm7---Eb7---AbMaj7---- becomes
Fm7---Bbm7---Eb7---Abdim7--AbMaj7--

I tend to overuse this when I play with singers, it's a nice sound though.

**Ashlee** · 10-19-2010, 10:18 AM

This may seem obvious, but what is a tonic?

**billkath** · 10-19-2010, 10:31 AM

Originally Posted by Ashlee

This may seem obvious, but what is a tonic?

Easy-it's what you put in your vodka!! Or-it's the root note of a scale. Or it's what Mammy gives me when I'm feeling a bit down in the dumps.

**derek** · 10-19-2010, 10:32 AM

Originally Posted by Ashlee

This may seem obvious, but what is a tonic?

The tonic is the I chord of the key you are operating in at the moment.

**FatJeff** · 10-19-2010, 10:49 AM

The "One" chord in any progression. It's the musical "home" (can be major or minor). Tonic (music) - Wikipedia, the free encyclopedia

**Ashlee** · 10-19-2010, 12:23 PM

Originally Posted by timscarey

Fully Diminished chords can also sub for the 1 chord. Usually at the end of a phrase when the melody is on the tonic. I call it a "Tonic Diminished" it happens in a lot of Jobim stuff like "Chega De Saudade" and a lot of old show tunes...

Fm7---Bbm7---Eb7---AbMaj7---- becomes
Fm7---Bbm7---Eb7---Abdim7--AbMaj7--

I tend to overuse this when I play with singers, it's a nice sound though.

Okay, (last question, I promise)

So, you said that the fully diminished chord can "sub" for the tonic chord. So does that mean you play it in PLACE OF the tonic chord, or right BEFORE you are going to the tonic chord?

In the example given in the chord progression above, it looks like a 6-2-5-1 (I think?).

And then you added the dim7 chord right before the tonic (see i'm using the new word I learned already) but you still played the I (Abmaj7)chord.

So it looks like you are using it as a passing chord, rather than a substitution? Is that right? anyone?

I may be misunderstanding the meaning of substitution and passing chords, so any help would be greatly appreciated!

Thanks!

**Jazzyteach65** · 10-19-2010, 12:23 PM

One way to employ them (diminished 7) which a lot of players do is for the sake of chord-soloing, chord-melody or reharmonizing tunes is as secondary dominants. That is, for every chord you have, especially if you're moving to it, to put a dominant chord a fifth above, and flat the ninth of the dominant 7th, which makes it a dim7. This diminished creates smooth tension-resolution.
ex: If I have Bb/c-7/d-7- I could go: Bb, G7/c-7, A7/d-7. Now, to make the transition even smoother, you would turn these dom7ths into 7b9's. If you sub the root with a b9, it makes the dom a diminished7. So, you would play: Bb, Bdim (G7b9) c-7, C#dim7 (A7b9) d-7.

Secondary dominants and diminished secondaries are used a lot in chord-melody, and chord soloing. Listen to Wes' chord-soloing ( I think there is a lesson on it here on the site) He would take say a d-7, but alternate between C#dim7 and d-7 to put a melody on top.

As far as m7b5, one way to use it is for a turnaround to the I, like Timscarey hinted at. For example, the tune "There Will Never Be Another You" is often changed by substituting the tonic (Eb) with a m7b5 up a tritone, to get: a-7b5,D7 /g-7, C7 /f-7, Bb7 leading to the tonic-Eb

**timscarey** · 10-19-2010, 05:07 PM

Originally Posted by Ashlee

Okay, (last question, I promise)

So, you said that the fully diminished chord can "sub" for the tonic chord. So does that mean you play it in PLACE OF the tonic chord, or right BEFORE you are going to the tonic chord?

In the example given in the chord progression above, it looks like a 6-2-5-1 (I think?).

And then you added the dim7 chord right before the tonic (see i'm using the new word I learned already) but you still played the I (Abmaj7)chord.

So it looks like you are using it as a passing chord, rather than a substitution? Is that right? anyone?

I may be misunderstanding the meaning of substitution and passing chords, so any help would be greatly appreciated!

Thanks!

Ashlee,

So I'm talking about putting the diminished on beat one, replacing the tonic chord for 2 beats and then resolving to the tonic on beat 3. so it's a substitution for 2 beats.

Abdim7 for the first half of the bar and AbMaj7 for the second.

**BigDaddyLoveHandles** · 10-19-2010, 05:13 PM

Maybe this is splitting hairs, but I would call that Abdim7 a passing chord. Certainly it introduces tension that gets resolved by the AbMaj7. But no matter what you call it, I like it!

**Reg** · 10-19-2010, 06:30 PM

Theoretical in jazz they're called an auxiliary diminished... the root of the Dim. chord is the same as the root of the chord of resolution. Usually the I or V of a key can be approached by Dim.7th built on same root. Delays the resolution to the target chord, or creates harmonic motion in static situation... Reg

**JohnRoss** · 10-19-2010, 08:48 PM

Originally Posted by timscarey

I'm talking about putting the diminished on beat one, replacing the tonic chord for 2 beats and then resolving to the tonic on beat 3. so it's a substitution for 2 beats.

It's certainly bloody interesting. It's probably just an upside-down suspension (retardation), on two of the chord intervals (third and fifth), while the bb7 of the Ab diminished chord stays where it is and becomes the sixth of the Ab. But it doesn't feel like a passing chord, I would have thought it was some kind of cadence, though I'm hard pushed to put a name to it. I might be flipping out, here, but it could be a kind of plagal cadence, if we can be perverse enough to consider the Ebb to be a raised Db instead. Let's see:

Ab Cb Ebb Gbb going to Ab C Eb F
could be spelt as
D F Ab Cb going to Ab C Eb F

which is the diminished seventh chord built on the augmented fourth (tritone, whoopee!) going to the tonic. Ergo plagal. Sort of. Vaguely. Probably not. Forget I said it.

**Ashlee** · 10-20-2010, 01:36 PM

Originally Posted by timscarey

Ashlee,

So I'm talking about putting the diminished on beat one, replacing the tonic chord for 2 beats and then resolving to the tonic on beat 3. so it's a substitution for 2 beats.

Abdim7 for the first half of the bar and AbMaj7 for the second.

Okay cool, gotcha! Thanks so much for your help!

**Reg** · 10-20-2010, 02:46 PM

Check out In a mellow tone, It's a raggy waltz or Spring is here. Used a lot in brazillan tunes... Reg

**CrackerJackLee** · 08-18-2018, 02:23 AM

Co7-CM7...?
It's Bali-Ha'i, Cap'n...! Bali- Ha'i...!
Break out the Kon-Tiki, me laddies...!

Now Peggy...! Hit us a tune... will ya!

**ragman1** · 08-18-2018, 07:10 AM

Originally Posted by timscarey

Half dim can also be a tritone sub for the 1 chord.

BbMaj7 - EbMaj7- Dmin - G7 becomes
Emin7(b5)- EbMaj7- Dmin - G7

Now that I didn't know. Learn something new every day.

**princeplanet** · 08-18-2018, 07:11 AM

For me, the half dim chord is usually used as a rootless Dom 9th and the Dim is a rootless Dom7b9. That is, apart from where they naturally occur "as is" in tunes

...

**Freel** · 08-18-2018, 07:40 AM

I got into this here.

Diminished Chords - DjangoBooks Forum

The intention was derailed, tediously, pretty sharp. But I tried to outline my limited understanding of diminished chords which seems to cover what I have seen in the little music I know in the long post at the start.

D.