Chord Substitution...Is It Plausible....

Discussion in 'Playing and Technique' started by gainiac, Jan 17, 2008.

  1. gainiac

    gainiac Senior Member

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    that substitutions came about simply because their is a certain more linear "smoothness" to harmony by grabbing a sub which is "closer" in terms of degree of pitch movements versus shifting through full blown voicings where root movements are more dramatic cadences?

    Just wondering this today as I was learning "All The Things You Are". Instead of going from DbMaj7 to G7 (bars 5 + 6) i used Dmin7b5 as a sub for G7.
     
  2. rosscoep

    rosscoep Member

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    I was taught that Roots Rool. So as long as your playing something where the root is being used as the guideline anything is possible. In the case of the dmin7b5 flat the seven is the major seventh of the db major chord. The flat three is the 3 of the db maj. the flat 5th would be the 5th of the db maj so those two chords are very closely related. The root movement might sound as a passing tone toward the resolution. I can't remember the next chord after the G7 so that would have something to do with it. If it sounds like it works then it does. IMO going outside is fantastic as long as the resolution is happening as you want it to.
     
  3. fetishfrog

    fetishfrog Member

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    I'd avoid Dmin7b5 instead of G7 because the C in the Dmin7b5 chord will rub with the B in the melody, unless that's what you are going for. You could use Dbmin7b5 instead of G7 as the Dbmin7b5 would be similar to a G13b5 type thing, resolving ever so nicely to Cmaj7. Anyhow, good luck.
     
  4. JonR

    JonR Member

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    IMO, yes.
    In jazz at least, root movement is not as important as guide tones: 3rds and 7ths. That's why tritone subs are so common. The 3rds and 7ths remain the same, but the root and 5th each shift by a tritone - so making chromatic moves in cycle-of-5th changes.
    That would be unusual, IMO, unless you had a 1/2 bar each of Dm7b5-G7.
    The function of the G7 is a cadence to C, and Dm7b5 doesn't quite work the same way. Almost (and maybe near enough) but not quite.
    But Dm7b5 is a kind of transition from Dbmaj7 to G7
    Code:
     
    Dbmaj7 Dm7b5 G7 Cmaj7
    C   >  C   > B > B
    Ab  >  Ab  > G > G
    F   >  F   > F > E
    Db  >  D   > D > C
    
    And yes, you could leave out the G7 - and there might be other intermediate chords to get other voice moves between the outer two. (Of course Dbmaj7 could just go straight to Cmaj7...)
     
  5. JohnM

    JohnM Member

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    Perhaps you meant to use Ddim7 as the sub for G7?
    That's a common tritone sub (both have B F tritone)

    One easy way to remember is you can play a dim7 chord from the 5th of any dom7 chord.
     
  6. gainiac

    gainiac Senior Member

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    That definitely seems to sound a bit better......!
     
  7. gainiac

    gainiac Senior Member

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    I'll try that next.........

    This stuff is making my rock playing deadly!
     
  8. gainiac

    gainiac Senior Member

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    Haven't gotten to the melody yet, that's a good point! I'm just memorizing a chart and goofing around....
     
  9. gainiac

    gainiac Senior Member

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    Next chord is Cmaj7........."Roots Rool" I'll take as the root is "covered" meaning if the bass has it (or someone else) all good?
     
  10. rosscoep

    rosscoep Member

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    Yes that is exactly what I meant.
     
  11. fetishfrog

    fetishfrog Member

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    Gotta love the melody. I always make sure what I am playing will be something that will complement the melody. Between this and the roots rule, you should have something like 5438 choices. :)
     
  12. JonR

    JonR Member

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    Everything begins with the melody! That's why those chords are there to start with.
    It's good to mess around with chords and see what works, but the melody gives you the essential guide. Any chord sub must harmonise the melody.

    I'd forgotten the melody note on the G7 was B, or I'd have mentioned that earlier. Of course, a melody note - in isolation - can be harmonised in a huge number of ways... but context (melodic, harmonic and rhythmic), will make some ways better.

    In this case, the melody notes in question (in that bar) are F and B. As well as G7, these can be harmonised by Db7 (tritone sub) and Ddim7 (= Fdim7, Bdim7, G#dim7) - both of which work well here.
    Dm7b5 would do for the initial F note, but the strong B demands something else. (And you need to bear in mind the 2nd F on beat 4, resolving down to E.)
    Others - closely related to those dim7s - would be E7b9 and Bb7b9. (Root movement here would be a little strange.)

    Generally speaking, once you get deeper into chord subs, you realise there's too much choice if you only look at the chords; almost any chord can move to almost any other chord! So the melody becomes a friendly guide.
     

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