Dm7b5 preferred over Dø

Discussion in 'General Instruction [BG]' started by ryco, Jun 28, 2008.

  1. ryco


    Apr 24, 2005
    So I've read more than a few times in this forum that some like to refer to a Dm7b5 opposed to Dø.
    Was wondering why in a functional harmony standpoint. Which is your preference and why?

    Dø = D F Ab C Eb G Bb
    When I see Dm7b5 I think: D F Ab C E G B
    or does it imply Dø#2: D F Ab C E G Bb ? (Locrian#2)

    I see: Dø > G7+9 > I more often than: Dm7b5 > G7+9 > I ; for ii - V7 - I progressions in particular. Any other places you prefer to use this chord/scale?

    Just curious since I've seen this POV expressed.
  2. DocBop


    Feb 22, 2007
    Los Angeles, CA
    To me of Cm7b5 and Cø are the same chord. Just different symbols for same chord. I also see a Cm7b5 as a dominant 9th without a root.

    Locrian is a basic scale to use over the chord.
    Locrian #2 is a more Coltrane-ish sound (mmi from 3rd of mi7b5)
  3. mutedeity


    Aug 27, 2007
    They are the same chord to you and everyone else Doc, they both have the notes {D F Ab C}. I don't know what ryco is trying to say with his post, but that chord can imply a lot of things, first and foremost, I guess it will imply Locrian in scale terms, but it could be attached to a lot of other scales.

    Also as Docbop said it can imply a dominant 9 without the root.

    I prefer to use Dim7(b5) in notation because it avoids any ambiguity or misreading of the symbol.
  4. EADG mx

    EADG mx

    Jul 4, 2005
    They are technically the same thing, I think people just prefer the name m7b5 because it's technically not "half" diminished but more "3/4" diminished.
  5. mutedeity


    Aug 27, 2007
    So "technically" what is half diminished? {1 b3 5 b7} or maybe {1 3 b5 b7}?
  6. ryco


    Apr 24, 2005
    What I was trying to say was I wasn't sure if both designations were for the same chord or not.
    When I see the half-diminished sign ø, I hear/think the locrian chord/scale.

    When I see the label m7b5, I think of a completely different series of notes.
    I have heard people here say they would rather see it written out m7b5 because it helps them to think of all the notes they have available and it's easier to read on the fly.
    What I am saying is I see the symbol on the fly and my brain flashes an altered Dorian with a flat five. Maybe I have Aebersold's Disease. :)

    The ø desinates half-diminished because the chord contains a minor 7th instead of a fully diminished 7 (enharmonic with a M6).

    I'm hip to the Dom9 w/o the root aspect. Cø could imply Ab7add9
  7. mutedeity


    Aug 27, 2007
    The answer is yes, they do mean the same thing, then.

    Now, what I want to know is how you get the "ø" sign in the first place when you type. I just cut and pasted it from your post, but is there are code for it?
  8. stoo


    Nov 10, 2003
    Alt + 0216 (hold down alt, type 0216 on the numeric keypad, let go of alt)


    You can look up symbols like that in the character map program (start / all programs / accessories / system tools )

    HTH :)
  9. DanielleMuscato


    Jun 19, 2004
    Columbia, Missouri, USA
    Endorsing Artist, Schroeder Cabinets
    That's how I'd read it.

    Good call; I'll have to remember that.
  10. ryco


    Apr 24, 2005
    I get ø by holding the "alt/option" key and pressing o.
    Can get Ø by holding "alt/option" + "shift" and pressing O.
    Different symbols for each key while holding down "alt", even more symbols if you hold down "shift" key as well.
    I'm on a mac  (alt/shift K); I don't know if this works on PCs

    I agree writing it out dim7b5 would eliminate ambiguity in my mind.
  11. ryco


    Apr 24, 2005
    I guess this thread is about nomenclature and how confusing it can be.

    Another thing that bothers me about the m7b5 designation would be referring to this as a minor chord at all. It clearly is a dim chord because it contains a diminished triad as its base = i - m3 - d5 .

    Also in keeping with this train of thought: in the original post example the G7 is altered with the designation V7+9. To my mind, on the fly, it looks like an Augmented chord. This could work because G7 alt is [G B D#] F Ab A# C#. But most players would emphasize a b5 (really a #4, C#) and not D#. I realize the "+' is referring to the #2, but reading quickly it looks like an Aug chord is implied. I alsounderstand this chord is borrowed from Mel min harmony.

    I can see why theory can be hard to grasp because one has to understand their are multiple ways to write the same thing. If you play long enough (and read), you grow accustomed to seeing these chord symbols and make your note selection. You know what the writer is asking for. But there is a kind of sloppiness about it. Maybe that's a good thing.
  12. onlyclave


    Oct 28, 2005
    never mind.
  13. PhatBasstard

    PhatBasstard Spector Dissector Supporting Member

    Feb 3, 2002
    Tacoma WA
    Not to derail, but somewhat related:

    I have always thought that if we are going to use "O" and "Ø" to denote diminished and half diminished respectively, for the sake of consistancy and due to the relationship of terminology, since "Ø" for half diminished, by definition is a chord taken to the 4th degree (b7), then it's related sister chord ("O" / diminished) should also automatically be taken to the 4th degree (bb7).

    "dim7" or "O7" has always seemed weird to me. When the 4th degree is unneeded it could be written simply as "mb5" or "-b5".

    My understanding of the implied scales is not up to many of your levels (I have a really good ear so I tend to play what I hear more than the mathmatics), so why am I wrong here?
  14. EADG mx

    EADG mx

    Jul 4, 2005
    The first one is min7

    Second would be altered

    dim7: 1 b3 b5 bb7

    half dim: 1 b3 b5 b7

    the half dim has 3/4 notes that make up the dim7. Therefore 3/4 diminished seems like a more suitable name than half diminished. Sorry I should have explained that earlier.
  15. LM Bass

    LM Bass

    Jul 19, 2002
    Vancouver, BC
    I like how Mark Levine (The Jazz Theory Book) sees it:

    Dø = 2 pieces of information

    Dmin7(b5) = 9 pieces of information
  16. HaVIC5


    Aug 22, 2003
    Brooklyn, NYC
    I think the reason why a lot of people prefer the nomenclature m7b5 (or -7(b5), or whatever) is because you see the "7" in the chord symbol, which is always nice to have, whereas simply "ø" doesn't have the visible 7 that we associate with 7th chords. Of course you could be redundant and do "ø7", which Jamie Aebersold does, I think. Regardlless of which way you symbolize it, though, its the same chord.

    From a very theoretical standpoint, you can make the case that there are two separate FUNCTION's that separate the structure 1 b3 b5 b7 into two different chords, the "minor 7 flat 5" and the "half-diminished", the same way that you would separate functioning and non-functioning dominant chords. If you have a regular minor ii-V, like Dm7(b5) - G7(b9) - Cm6 or whathave you, the first chord would have subdominant, or predominant function, the same as its corresponding minor 7 chord would have if it were a major ii-V. There is a change of modality (major to minor), but the chord's function remain's the same within the chord progression. If, however, you had a CHROMATIC chord progression that related in the same way that diminished chords relate to others (descending/ascending by half-steps), then you would have something different. What I mean by that is something like the second half of the A in Night and Day, when you have a chord progression like F#m7(b5) - Fm7 - Em7 - Eb7 - Dm7 - G7. The F#m7(b5) has a diminished function, but isn't a fully diminished chord, hence, "half-diminished".

    The reason why the term "half-diminished" came into vogue in the first place was because of a chord progression that behaved similarly. The beginning of Tristan and Isolde by Wagner starts dramatically on this chord and the voices all move chromatically towards resolution. You'll hear some classical people call it the "Tristan" chord for that reason.
  17. DocBop


    Feb 22, 2007
    Los Angeles, CA
    IMO for the dim or "O" chord it doesn't matter how far your build it out because it is a symmetric chord. Remember in a dim chord any note of the chord can be its root.
  18. Johnny StingRay

    Johnny StingRay Guest

    Nov 24, 2006
    This is quoting from Carol Kaye's Jazz Improv for Bass book, page 21 about subbing for the m7b5:

    "m7b5 = Use the minor chord 3 frets higher: For F#m7b5 (which is also called F# 1/2 diminished - no it's not a diminished chord at all , just a term) use Am7, OR, use the 7th it's going to as a diminished: F#m7b5 goes to B7, so use Cdim over both chords, OR, use the pivotal b5 of B7 (F13, F9, or Cm9 - again only if the B7 is resolving to its tonic of the E chord), or use the major note scale 1 fret higher than the m7b5 chord: F#m7b5 is the maj7 degree of the G note-scale, but this is a sort of a last-resort, don't use note-scales much, they are boring and non-melodic - notes scales are OK a few times, but usually only as traveling notes." :meh:

    This is for jazz improv/soloing. After reading all of that and trying to remember it while I'm playing:meh:............I just came to the conclusion that playing ANY note, whether it is right or wrong, can be justified in jazz improv!!!!!! In my Christian group I always tease the members by saying, "I never play a wrong note on my bass......................if it sounds wrong, I just call it JAZZ!!!" Jazz for Jesus..........a nice little alliteration!:D

    She also said that the symbol for m7b5 the 0 with the slash through it, was first used because some writer got tired of writing m7b5 over and over again, that's all there is to that.;)

  19. mutedeity


    Aug 27, 2007
    I understood you perfectly actually. I was really making the point that it's not called half diminished because it has half of the notes of whole diminished. It's just nomenclature and it's not at all misleading in my opinion.

    I was also pointing out that calling something else half diminished based on the logic you are applying doesn't work as far as I can see.
  20. mutedeity


    Aug 27, 2007
    Yes, and also a diminished chord is one of Messiaen's modes of limited transposition, having only 3 transpositions.