Author Topic: JA-029 • Diminished as a 7b9 Chord  (Read 8873 times)

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Offline justinguitar

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« Last Edit: October 25, 2021, 10:31:51 am by close2u »
"You can get help from teachers, but you are going to have to learn a lot by yourself, sitting alone in a room." Dr. Seuss

Offline willie nik

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Re: JA-029 • Diminished as a 7b9 Chord
« Reply #1 on: April 22, 2010, 04:38:53 pm »
Sometimes you refer to these chords as diminished chords, and sometimes as dim7 chords. Is there a difference?

Offline TB-AV

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Re: JA-029 • Diminished as a 7b9 Chord
« Reply #2 on: April 22, 2010, 05:08:14 pm »
Can't find the exact spot you mention but a diminished chord is a special type of 7th chord. what he was trying to get across, I believe, is simply to ...

diminish an otherwise 7th chord. Or rather substitute a diminished chord for an otherwise normal 7th chord. Also don't confuse when he says Dmin7 ( D minor Seventh ) that's simply the ii chord in his example.

Dm7 G7 Ab-dim(G#-dim)


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Re: JA-029 • Diminished as a 7b9 Chord
« Reply #3 on: November 23, 2012, 02:06:35 am »
One thing that really excited me when I discovered that the notes in the diminished grip stayed the same when moved up 3 frets (especially in relation to this lesson) was when I looked at each diminished shape as I moved it up the neck and realised that I only had to move one note backward one semitone to get to one of the 5 CAGED dominant 7th shapes. Not only that - but the note you move back willbe the root note :) cool eh!

It gets even better than that, Justin.  Move any tone in the diminished-7th chord up a half tone and you've got a half-diminished-7th chord.  The tone you just moved up is the 7th and the root is a whole step above that. 

That chord is also the top of a dominant-9 chord (no root).  The root will be a whole step below the tone that just moved.

And to top it all off, it's also a minor-6 chord.  The root the minor 6 can be found a minor third above the root of the half-dim-7th chord.  The minor 6 is a very important chord in minor jazz harmony and can suggest a melodic minor scale.

So, if you play a B-dim-th chord and move G# to A-natural, you have:
  • B-half-diminished
  • G-9 (no root)
Check out Pat Martino's Sacred Geometry article  www dot patmartino dot com /Articles/GuitarPlayer_April_2004.pdf.

The other thing I just noticed is that all three types of chords have the same tri-tone interval, but I'm not yet sure what the significance of that might be, except that they can all be thought of as an extension of the Dom-7th chord whose root we omitted.

That's the thing about theory: I'm a computer and music nerd and love to read music theory books, so I could go on for hours boring you to death, but only listening and practice will help me play any better.

If you have nothing to do and want to try a real brain-twister, try to get your hand's on a copy of "The Lydian Chromatic Theory" by George Russel.  I first heard about it by reading a comment on a YouTube video that featured John Scofield playing with Pat Martino.  The commenter said that Martino's solo style is old school be-bop and Cool Jazz, while Scofield's is Lydian Chromatic which is used a lot in Motown.  I still have no idea what that means, but am dying to know more.  I suspect that by "Motown", the poster really may have meant Gospel, from which Motown really derives, but I'm just guessing here. 

I read that Russel worked with Ornette Coleman in the 50's who's music (to me) is so out there it's almost unlistenable.  It's out of print and copies go for well over $100 on Amazon, but you might be able to download a bootleg copy somewhere. 

Offline nkvigno9

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Re: JA-029 • Diminished as a 7b9 Chord
« Reply #4 on: September 14, 2015, 09:28:11 pm »
Hi Justin, thanks for everything.

This is something I noticed in this context, don't know if there's a theoretical connection.

If you take a ii V I in C, that is:  Dm7/G7/Cmaj7

and substitute for V7, a dim7 chord with root a half step BELOW V -- in this case, F#dim7 --

You get the first half of the basic motif of April In Paris.

i.e. in one measure:

(triplet quarter notes) Dm7/Dm7/Dm7

(quarter note) F#dim7

(quarter note) Cmaj7

The sub is Idim7 for ii7. 

This is what happens when you thought you had an insight!
« Last Edit: September 14, 2015, 11:38:14 pm by nkvigno9 »

Offline 4decopas

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Re: JA-029 • Diminished as a 7b9 Chord
« Reply #5 on: December 01, 2015, 01:49:00 am »
Hi Justin, greatings from Argentina!
 Great lesson as always.
is there a lesson strictly on diminished chords made already? cause if there is i havent found it.
One thing i was noticing (perhaps it was the whole purpose of your lesson i don´t know) is that if you replace the G7 with the G#dim, because of the notes in common is the same as saying that what you are actually doing is replacing G7 with Ddim (and D is the fifth grade of G so thats another quick way of finding the diminished "relative" of a given dominant chord!)

Reading this again, diminished chords theory sounds like rocket science to me, but hey it works and sounds great.


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