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Tritone substitution

Discussion in 'Music Theory [DB]' started by Mark Steel, Feb 9, 2001.

  1. Hi all--a funny thing happened on the way to double bass playing--suddenly started listening (and loving) jazz and also decided to delve deeper into aspects of music theory. What is it about this instrument?
    Anyway, would like it if someone would explain tritone substitutions and how they might be useful in the real world. My take thus far--you are swapping the III chord in a scale with a chord 3 steps up. Is this correct? Does everyone do this or do you arpeggiate the subst. while the others stick with the original chord? Does this make sense?

    oops--meant the V chord, not the III. Won't edit in case someone is responding as I type.

    [Edited by double dad on 02-09-2001 at 08:15 AM]
  2. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator

    Oct 19, 2000
    Louisville, KY
    Technically speaking, a tritone substitution generally refers to substituting one dominant chord for another which shares the same tritone.


    7th...3rd (B is an enharmonic spelling of Cb)

    The net tonal effect of using a dominant tritone sub is the same as altering the dominant chord while changing the bass to a note that typically resolves down by half-step. For example, the following are common piano voicings for both chords (assume enharmonic spellings):

    7th..9th..3rd...6th (a common color tone for Dom7 voicings)

    In many cases it is best to use a lydian dominant scale for the Db7, which makes it the same scale that would be used for the G7#9(#5), as they are modes of each other. Don't worry about which is the "chicken" and which is the "egg" - it really doesn't matter.

    As a bassist, if you are going to use dominant tritone subs a lot (many folks even "sub" entire ii-V progressions, but that's another story), it helps to be playing with a pianist/guitarist who has big enough ears to do the following on the spot - either:

    a)alter the dominant chord appropriately when hearing the bass note change, or
    b)switch to the related "sub" chord, which usually amounts to the same thing.

    Hope this wasn't too confusing.

  3. This kind of bumps into the reservation I have about a theory discussion board. It's so much harder to convey the information without the student and the piano being right there. An explanation can be accurate without necessarily being understandable. That's an underestimated art. And that may be the part that intimidates the lurkers. They think that if they don't get the explanation, it's their fault. Not necessarily, folks. If you don't get something, ask again, just the way I had to re-explain my "Explain the shift" theory. It's my obligation to make it clear.

    Now we're into a second theory thread, still in the Miscellaneous board. I think we should move. I have some random things on different aspects that could be helpful, but I don't know where to put them so that newbies can find them.
  4. Thanks Chris and Don--I will definitely have to get the piano and bass and play around with this--I'm not one to "grasp" spoken or written ideas as much as the "hands on" approach.
    When I spell out the lydian dominant scale I get a G# (assuming #4, b7). What am I doing wrong?
    Should this be under technique, or are we trying to get admin to create a new DB topic?
  5. To add to what Chris wrote, the defining feature of any dominant chord (V7) is the presence of a tritone between the third and seventh intervals of the chord. A tritone is half and octave, this causes it to sound the same regardless of which note is on top or on the bottom. In other words, an inverted tritone is still a tritone, unlike a third which inverts to a sixth. Ya still with me? The result is that you can spell V7 chords a tritone apart and the the notes forming the tritone within the chord will remain the same.

    As I mentioned the tritone is the defining feature of the V7, so it stands to reason that V7 chords a tritone apart, containing the same tritone will function in an identical manner.

    Example: Dm7->G7->Cmaj7 = Dm7->Db7->Cmaj7
    ii7->V7->Imaj7 = ii7->bII7->Imaj7

    Check out the chromatic motion in the example on the left. That's probably the most common use of the tritone sub.

    I wanted the roman numerals to line up w/the chords in the line above but couldn't do it. Picture that part lined up

    [Edited by David Kaczorowski on 02-09-2001 at 01:55 PM]
  6. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator

    Oct 19, 2000
    Louisville, KY
    If you're trying to spell a lydian dominant scale in Db, it would be:
    Db, Eb, F, G, Ab, Bb, Cb(B), Db

    Is that what you were asking?

    By the way, I'm sure most people knew this already, but for any "Silent Lurkers" who might be confused, those voicings in my last post were rootless; that is to say, they were what a pianist might play if (s)he was assuming that the root was going to be played by the bass. You'll have to plunk out the root along with them on the piano if you are alone.

    About the other thing, I agree we should have a dedicated Theory Topic (or Forum, or whatever it's called)...how do we go about requesting that?
  7. Yes Chris, that's what I meant. Thanks.
  8. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator

    Oct 19, 2000
    Louisville, KY

    I had the same problem about things lining up. Theory without notation is difficult! To get things to line up I have to use these........as.........spacers. It's a pain, but it seems to work most of the time.
  9. A Lydian Db is a Db scale played on an Ab key signature. Then minor the 7th (C becomes Cb, which is the same note as the 3rd in a G7 chord). In essence, Db7-5 = G7-5. You can find this device in Mozart's Requiem, among other places.

    Now, you can get a headache with this by questioning whether a G natural in a Db chord is a flatted 5th (Abb) or an augmented 4th (Gb raised to G) or, to impress the folks, an augmented 11th. The ear doesn't care. Use it. Enjoy it.

    May I add that I don't know what the hell I did to cause the capital letters. You know that's not my style

    Wow. That's embarassing.

    [Edited by Don Higdon on 02-09-2001 at 02:11 PM]
  10. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator

    Oct 19, 2000
    Louisville, KY

    That was pretty funny. I suspect that for some unknown reason, you pressed [ , B , ] , only without the commas. To cancel, press [ , / , B , ] . That usually cancels it.
  11. [,B/,] This is a test. Stop laughing, dammit. What happened was, I wanted to put Cb(B) with the B in brackets since I was already inside parens.

    [Edited by Don Higdon on 02-09-2001 at 02:25 PM]
  12. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator

    Oct 19, 2000
    Louisville, KY
    I can't help it...everytime I even think about the above sentence in total visual context, it makes my ribs hurt. Sorry...but hey, you made someone's day without even trying.That ought to be worth something, right?

    P.S. - I'll tell you how to control that in the future if you'll promise not to change the original post until everybody has had a chance to see it. Waddaya say?
  13. Proudly, I accept my new sobriquet. I even prefer it.
    With this post, I solemnly vow always, with vigor and dedication, to justify the faith you have expressed by living down to the expectations implicit in the title you have bestowed upon me.

    [Edited by Don Higdon on 02-09-2001 at 03:07 PM]
  14. Thanks for explaining the boldface type, Don--I was afraid you lost it partway through and were yelling at me!

    Example: Dm7->G7->Cmaj7 = Dm7->Db7->Cmaj7
    ii7->V7->Imaj7 = ii7->bII7->Imaj7

    does this mean that the tritone sub chord is always one-half step up from the chord it resolves to? Seems like an easy way to "grab" it quickly.

    still have to grab the bass and play over this stuff.

  15. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator

    Oct 19, 2000
    Louisville, KY
    Yep, that's what it means, which makes it a pretty easy "grab" for most of us bassplayers. You can choose to do it almost at will in any minor ii-V-i, since it is pretty much assumed that the V chord will be altered anyway...but remember - if YOU choose to stick in a tritone sub in a major key ii-V-I and the piano player DOESN'T catch it (and therefore doesn't alter his V7 voicing) things can get pretty messy pretty fast. Lots of trial and error in the practice room is advised before whipping a bunch of these out on a gig with an unsuspecting pianist/soloist.

    David - sorry if I stole yer thunder. I was taking a practice/dinner break & couldn't control my itchy post finger...
  16. I have no thunder, Chris.

  17. I was rehearsing with a piano player last night and he suggested I use the tritone sustitution of a particular chord. I asked him how he consrtucted the tritone sub (and what that exactly meant). But, he isn't very articulate (in fact he's a little bit of a bully). So I'm running to the comfort of the dark castle to see if I could gleen any insight from you guys.

    I ran a search for "tritone substitutions" and came across this thread, but I'm still not getting it.

    I understand now that a tritone sub is 6 half steps up (or 3 whole tones) from the chord you are subbing, but I don't understand why or how this works. My pianist buddy said something about splitting the octave? :confused:

    From reading this I'm not sure if you apply it to only the V chord of the scale or if it can be applied to the whole scale?

    Many Thanks
  18. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator

    Oct 19, 2000
    Louisville, KY

    I'm not sure I understand your question. Could you be more specific, and perhaps post an example or two? It would be easier to illustrate Tritone sub questions with some specific material to work with.
  19. Okay, Thanks

    I was just rereading the thread on Melodic Soloing and Blanket Scales. It answered most of my questions.

    I'm going to spend some more time exploring the theory links. Again, thank you.
  20. Joe Taylor

    Joe Taylor

    Dec 20, 2001
    Tracy CA
    I alway thought the tri-tone was the aug 4th or dim 5th as in a to e flat also called the devil in music. I was instructed to do almost anyting to avoid that interval.


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