No Root Chords

[JimmyK]

Is there an easy way to identify chords that don't have a Root?

[JonR]

I don't think there's an "easy" way. The way I do it is a combination of visual recognition (what chord does it look like part of?) and theory: knowing which notes are in which chords (and of course which note is on which fret!). Enharmonic equivalents can also be important (is that D# or Eb?).

There would normally also be clues in the context: the chords before and after - meaning you need to recognise typical chord progressions. (I'm assuming there isn't a bass actually playing the root...)

Obviously, experience and some theory knowledge underlies all this. (I'm not aware of "short cuts", because it only takes me a second or two to work through this process; maybe a little longer to recognise possible alternative names.)

Can you maybe give some examples? (chords you don't recognise and think might be rootless?) Are you seeing these chords in notation, or finding them yourself on guitar?

[gingerjazz]

I agree with everything Jonr has said above.If you could tell us a little more about what it is you are having trouble with we may be able to help better.As Jonr says it really does depend on context many rootless chords can function as more than just one chord(the same notes may be contained in more than one chord) so without a specific example it would be difficult to say what a rootless chord was in isolation.Hope this helps a bit.It may also help if you could mention your level of understanding on music theory as without some basic theory knowledge it will be hard for a person to grasp the concept.Peace.

[JimmyK]

The chord causing the consternation is F7b9. the notation is C , Gb, A-natural, Eb; but I see the F7b9 as F.... A, C, Eb, Gb. However, I've been studying the relationship between the Dominant 7b9 chord and the Diminished 7th chord. Finally getting the message that the Root of the Diminished 7th chord is the Third of the 7b9th chord, and the reverse is also true. That said, I took the A (3rd of F) and called it the Diminished seventh chord or A, C, Eb and Gb. Reversed it backwards and arrived at the F7b9. It appears from your comments that there isn't any "Easy Way"; can't wait to try the Extended and Altered chords.
I've done home study for years and thought my pedestrian way was circuitous; and there would be a more sophisticated approach. Apparently not!
Thank You

[brwnhornet59]

Take F7, F A C Eb and raise the root 1/2 step. What do you have? You can call it a rootless F7b9, or F#o depending on function. Is the chord leading back to Bb? If yes it has a dom function (F7b9).

Is the chord leading to G-7 (FM7 F#o G-7)? If so it is being used as a passing chord. Same if it is leading to F ( G-7 Gbo F-)


The cool thing about 7b9 and dim relationships is you can take the dim chord or any of its 3 inversions and imply four key centers by moving up or down in minor 3rds.

F#o (F7b9) = F7

Ao = Ab7

Co = B7

Ebo = D7

This is just a few ways to look at it. I am sure more people will give their POV promptly..

[swampguide]

You can try to look for a 3rd and 7th (either major, minor and dominant) in the chord and go from there. For example if you see E-B -> CM7, Eb-Bb -> Cm7, E-Bb -> C7. Other notes in the chord could be colour and/or altered tones. Of course sometimes you could still have ambiguities in deciding on which chord it is. In your example (as I'm sure you noticed) A-Eb -> 3-7.

[gingerjazz]

Sorry i cannot add anything to Brwnhornets answer ,in fact if i am being honest he is more articulate than me.If you pm me Brwnhornet i will tell you where to send the cheque.Peace.

[cosmic gumbo]

Without a bassline, or without context, there is no way of determining a specific chord with a rootless voicing.

[jazzadellic]

Hey JonR, I'm assuming you are the same JonR that used to post on guitar.com theory forums, before they ruined the website and drove everybody away. Good to see you. Gee that must have been like 10+ years ago when I used to talk theory with you on there ;o) Everybody, listen to JonR, he's the man! ;o)

[jazzadellic]

I don't think there's an "easy" way. The way I do it is a combination of visual recognition (what chord does it look like part of?) and theory: knowing which notes are in which chords (and of course which note is on which fret!). Enharmonic equivalents can also be important (is that D# or Eb?).

There would normally also be clues in the context: the chords before and after - meaning you need to recognise typical chord progressions. (I'm assuming there isn't a bass actually playing the root...)

Obviously, experience and some theory knowledge underlies all this. (I'm not aware of "short cuts", because it only takes me a second or two to work through this process; maybe a little longer to recognise possible alternative names.)

Can you maybe give some examples? (chords you don't recognise and think might be rootless?) Are you seeing these chords in notation, or finding them yourself on guitar?

Oh and I just want to add, it also helps if you know tons of jazz tunes. After a while you just begin to see the same jazz chord patterns over and over again, and even a sparsely comped set of changes can be easily identified. It doesn't hurt to have a ton of fake books too, and just look up the tune ;o)

[JonR]

The chord causing the consternation is F7b9. the notation is C , Gb, A-natural, Eb; but I see the F7b9 as F.... A, C, Eb, Gb. However, I've been studying the relationship between the Dominant 7b9 chord and the Diminished 7th chord. Finally getting the message that the Root of the Diminished 7th chord is the Third of the 7b9th chord, and the reverse is also true. That said, I took the A (3rd of F) and called it the Diminished seventh chord or A, C, Eb and Gb. Reversed it backwards and arrived at the F7b9.

The connection here is the Bb harmonic minor scale: Bb C Db Eb F Gb A.
F7 is the V7 chord in Bb harmonic minor, and Adim7 is the vii7 chord. (These would be the normal V and vii chords in the Bb minor key, the other chords coming from natural minor; althought arguably the tonic would come from Bb melodic minor.)
Both of them have the same dominant function - resolving to Bbm.
Combining the two together (for max dominant function! ) results in F7b9.
And of course, it's common in jazz for the bass to take the root, so that piano or guitar doesn't need to. (It not being cool in jazz to double up what someone else is playing... )

It appears from your comments that there isn't any "Easy Way"; can't wait to try the Extended and Altered chords.

That's where the fun really starts...

[JonR]

Hey JonR, I'm assuming you are the same JonR that used to post on guitar.com theory forums, before they ruined the website and drove everybody away. Good to see you. Gee that must have been like 10+ years ago when I used to talk theory with you on there ;o)

That's me.

Everybody, listen to JonR, he's the man! ;o)

[blush]. Thanks, but there are a few other "men" around here . (I never feel quite grown up in serious jazz company.)

[JimmyK]

Context and Progressions will get a lot more attention in the future.

Many Thanks to everyone for your time and comments.

Regards,

Jim

[jazzadellic]

I've been studying the relationship between the Dominant 7b9 chord and the Diminished 7th chord. Finally getting the message that the Root of the Diminished 7th chord is the Third of the 7b9th chord, and the reverse is also true.

It's a bit more complicated than that. First off, any note in a dim 7 chord can be the root, since it is made up of stacked minor thirds, no matter which note you start from, you still get the same intervals and same chord. For this reason, there actually only exists three unique diminished 7 chords (if you just look at the notes, not considering octaves / inversions / enharmonic spellings). Secondly, a dim 7 chord can actually be a substitute for four different dominant 7 chords. And any note in the dim 7 chord can be the 3, 5, b7, or b9, depending on which dominant 7 chord it is substituting for

[JonR]

It's a bit more complicated than that. First off, any note in a dim 7 chord can be the root, since it is made up of stacked minor thirds, no matter which note you start from, you still get the same intervals and same chord. For this reason, there actually only exists three unique diminished 7 chords (if you just look at the notes, not considering octaves / inversions / enharmonic spellings). Secondly, a dim 7 chord can actually be a substitute for four different dominant 7 chords. And any note in the dim 7 chord can be the 3, 5, b7, or b9, depending on which dominant 7 chord it is substituting for

Very true - but I like to begin (as JimmyK is saying) from the harmonic minor vii derivation of the chord, as a way of understanding its diatonic relationship with one dom7 to begin with; which helps explain how it works in a dominant role.

Of course, it escapes that limitation easily, as you say, becoming detached from its origin, or rather becoming able to refer to 4 different key centres.
So Bdim7 begins in C minor (as vii7, or rootless G7b9); but (with enharmonic re-spelling if we want to be pedantic) it can become Ddim7 (in Eb minor), E#dim7 (in F# minor), and G#dim7 (in A minor). All without having to change the shape or voicing at all .

And just to add: Jazz CST convention aids this multi-key ambiguity by associating the chord with the WH dim scale, not with 7th mode harmonic minor. (WH dim has no avoid notes.)
So need to switch scales, any more than there is to switch chord shape .

(BTW, I don't really think of WH dim as a scale, but as the chord arpeggio plus half-steps below each chord tone - ie another dim7 arp a half-step down. So it's a scale consisting entirely of chord tones and chromatic approaches. Thats how it works for me.)

[Steve Montgomery]

I see you guys are talking about rootless chords and dimished chords. Check this thing I did for YouTube. Most of the chords are rootless (but I have some subjective labels flash on the screen). Then at about 1:08 I have some diminished voicings that aren't normally used by guitar players. Tell me what you think (other than the playing's a bit rough, I'm going to edit it a bit and then redo it)