How to resolve the diminished sound

[Zappafreak]

So im working on this progression.. more like a 2 chord change between Am7 to Bdim, and im trying to understand how to resolve the diminished sound. Whats the theory behind it?

[stevel]

So im working on this progression.. more like a 2 chord change between Am7 to Bdim, and im trying to understand how to resolve the diminished sound. Whats the theory behind it?

I'm going to assume you mean Bdim7 since most people include the 7 when they say "dim" in a jazz context (since you started with Am7).

A diminished 7th chord can resolve a number of ways but the most common "resolution" is for the root note to ascend one half step.

So, G#o7 would resolve to A or Am.

However, there's a catch: Dim7 chords are actually symmetrical and any of the four notes could be heard as the root. So, your Bdim7 is spelled B-D-F-Ab.

This means it is:
Bo7
Do7
Fo7 and
Abo7

So it could resolve to C or Cm (as Bo7), Eb or Ebm (as Do7), Gb or Gbm (as Fo7).

Ab can't really resolve to Bbb or Bbbm, so instead we treat it enharmonically as G#o7 which would resolve to A or Am.

Likewise, the Fo7 could be thought of as an E#o7 and resolve to F# or Fm.

Historically, composers often treated them as "non-spelling-dependent" meaning they spell it the way it should resolve when practical, but when you get into too many double sharps or flats, they just spell it a simpler way. What we call it is usually based on the resolution, not the spelling in those contexts.

So in effect, your Bo7 could resolve to Am (as an inversion of G#o7) or C.

Notice that the notes in a dim7 chord are a minor 3rd (3 frets) apart, and that they can each resolve to a major or minor key (or chord) a half step above meaning the possible resolutions are a minor 3rd apart as well.

Diminished 7 chords can also be used as passing chords or what are called "common tone diminished 7th chords" (cto7) and they don't "resolve" in the traditional sense but typically provide chromatic voice-leading that's very logical and smooth sounding.

Em7 - Ebo7 - Dm7 is a passing type

G - Go7 (or Eo7, etc.) - G is a common tone type.

HTH,
Steve

[jamester]

Think of Bdim7 as E7b9/B (no root), cuz that's what it's functioning as.

So basically you've got a simple V7 - i. Approaching it that way should make the resolutions simple and obvious; basically learn to see/hear where the chord tones want to resolve:

B - A or C
D - C or E
F - E or G
Ab/G# - A

Half-step resolutions are stronger than whole steps. Treat the Ab/G# as a leading tone to A; even though resolving down to G would be technically fine, it won't be as strong or as pleasing as resolving up to the Root.

Of course, context is everything, these are just theoretical guidelines...

[Baminated]

RE: on everyone above - great insights

B diminished 7 arp (Bº7) tones are B D F Ab

E dominant 7 arp tones are E G#/Ab B D

Note that three (3) tones are shared in common (B, D, & G#/Ab)

The "E" distinguished the E7 arp, while the "F" distinguishes the Bº7 arp

Does that make sense so far ?

[Trebor Renkluaf]

Here's a cool thing about full diminished chords I'm sure everyone knows: if you lower any one note in the chord a half step you end up with a dominant 7th chord:

In your case start with the b diminished chord B D F Ab, let's lower the F first and it becomes E G# (enharmonic with Ab) B D - E7. E7 is the 5th of A so you can resolve to A or Amin.

Next lets lower the B and we get Bd D F Ab - Bb7. Bb7 is the 5th of Eb so you can resolve to Eb or Ebmin,

Next lets lower the D and we get Db F Ab Cb (enharmonic with B) - Db7. Db7 is the 5th of Gb so you can resolve to Gb or Gbmin.

Next lets lower the Ab and we get G B D F - G7. G7 is the 5th of C so you can resolve to C or Cmin.

Your diminished chord can resolve to any of the above.

Diminished chords are pretty darn cool!

[gennation]

A dim7 chord resolves nicely a half step up to a minor chord, like Gbdim7->Am.

Or it can resolve nicely a whole step down to a minor chord, like Bdim7->Am.

I'm sure someone has already brought up this type of move and they both equal a V7-Im move. So it this case both of those are E7->Am.

So, "in theory" your Bdim move to Am, Am IS the resolve point.

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

You can use it this way too within a progression where minor chords are present...

||: Fmaj7 | Dm7 | Gm7 | C7 :|| becomes...

||: Fmaj7 C#dim7 | Dm7 F#dim7 | Gm7 C#9 | C7 Edim7 :||

In each case the dim7 chord is th V7 of the chord that follows it, like...

||: Fmaj7 A7 | Dm7 D7 | Gm7 C#9 | C7 :||

[guitarjazz]

The first five pages of Joe Pass Guitar Style has some very practical insight into how chords, including diminished, function and move.

[slyzspyz]

Here's a cool thing about full diminished chords I'm sure everyone knows: if you lower any one note in the chord a half step you end up with a dominant 7th chord:

the clue is in the name "Diminished" "Seventh" ie you take a seventh chord, and diminish it (flatten all the notes, except the root of course). Which is the same result in reverse, albeit a semitone away, from just flattening one of the notes to reveal a new tonic. This is also why a Dim7th belongs to the Dominant family and a Diminished Triad is from the minor family. I also think calling a m7b5 a "half diminished' is kind of misleading.

As well as being a substitute for a V7b9 chord, a dim7th can also resolve by "undiminishing" itself eg Cdim7 can resolve to C7

To the OP's actual question, everyone's chimed in with lots of interesting theory, but not sure if it has been answered - maybe he's asking what to play over the chords, in which case the simplest answer IMO is on Am7 play whatever sounds good to you (blues, dorian etc) and try A Harmonic minor on the Bdim chord (whilst de-emphasising the actual A note, treating it as an E7 phrygian dominant)

[jamester]

t
To the OP's actual question, everyone's chimed in with lots of interesting theory, but not sure if it has been answered - maybe he's asking what to play over the chords...
Perhaps the OP can clarify exactly what he's looking for..?

The basic question has definitely been answered though; in the example, there are only two chords. Assuming the Dim chord isn't the "one" chord, it is simply E7b9 going to Am7, V7 to i. Bdim is simply an enharmonic spelling of E7b9, it is a Dominant functioning chord resolving to its Minor tonic.

As for what to play over it, well that's a whole other thing. The most simple would indeed be A harm. min., using target notes/arpeggios to outline/emphasize either the Am or the E7/Bdim. By nailing those target notes/chord tones, the resolutions will take care of themselves...

[JonR]

the clue is in the name "Diminished" "Seventh" ie you take a seventh chord, and diminish it (flatten all the notes, except the root of course). Which is the same result in reverse, albeit a semitone away, from just flattening one of the notes to reveal a new tonic. This is also why a Dim7th belongs to the Dominant family and a Diminished Triad is from the minor family. I also think calling a m7b5 a "half diminished' is kind of misleading.The way I look at it is this:

1. The dim7 chord derives from the vii step of the harmonic minor scale. Eg, in A minor, the chord is G#-B-D-F.
G#-F is the "diminished 7th" interval (half-step smaller than a minor 7th), which I see as the origin of the chord name.

2. The dim7 chord has two diminished intervals - 5th and 7th (the 3rd is minor). The m7b5 chord only has one (the 5th); hence "half-diminished". (I'm not saying this is a "right answer"; I just like the logic of it ;))

3. As in the major key, both V and vii chords have a dominant function (they resolve to the tonic). In both cases, the vii can be seen as a rootless dominant 7th, and the vii7 as a rootless dominant 9th, which is why it's a good substitute.
Eg, in A minor, G#dim7 is a rootless E7b9.

As well as being a substitute for a V7b9 chord, a dim7th can also resolve by "undiminishing" itself eg Cdim7 can resolve to C7True. This is the "common tone diminished" move, as steve described.

That's where the chord construction makes sense as you described it: retaining the root, but lowering every other note by a half-step. (Strictly speaking, only the 5th and 7th are "diminished"; the 3rd changes from major to minor.)

cto7 chords also resolve (if steve doesn't mind me using that word ;)) to tonics and IV chords, of course, not just V7s. (AFAIK, they don't resolve to minors, but I guess they could...)

To the OP's actual question, everyone's chimed in with lots of interesting theory, but not sure if it has been answeredHe was asking "how to resolve the diminished sound" - that sounds like a harmony/chord progression question, not an improvisation question; and it has been answered.
Which doesn't mean we can't add some interesting extra info, or even repeat what someone already said (in a hopefully usefully different way)...;)

- maybe he's asking what to play over the chords, in which case the simplest answer IMO is on Am7 play whatever sounds good to you (blues, dorian etc) and try A Harmonic minor on the Bdim chord (whilst de-emphasising the actual A note, treating it as an E7 phrygian dominant)Yes - if we think of Bdim7 as just an inverted G#dim7 (as steve was saying), A harmonic minor is the obvious choice, seeing as that's the scale it comes from.

Of course, steve is also right that - strictly speaking - Bdim7 belongs to C minor (because it contains an Ab, not a G#).
But then - as we've all said - the symmetry of dim7 chords makes them capable of being heard 4 different ways, and therefore resolving 4 different ways.

[stevel]

cto7 chords also resolve (if steve doesn't mind me using that word ;)) to tonics and IV chords, of course, not just V7s. (AFAIK, they don't resolve to minors, but I guess they could...)


Traditionally, they didn't resolve to minors. Since you'd have two common tones, the effect of the resolution would be diminished :rimshot.

Steve

[JonR]

Traditionally, they didn't resolve to minors. Since you'd have two common tones, the effect of the resolution would be diminished :rimshot.

SteveLOL [...struggling to resist launching into the traditional string of music-based puns...]