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Question about Triads.

Discussion in 'General Instruction [BG]' started by Feda, Apr 1, 2005.


  1. Feda

    Feda Screwed up pitch

    Jan 12, 2004
    Bergen, Norway
    Let's say I have a Bbmajor scale. The seventh degree would be A. Now, are the triads:

    A-Cb-Ebb-Gb

    Since it's the seventh degree that would a Amin7b5 chord right? Whats bothering me is that the Bbmajor scale has an Eb in it. Does this mean that I have to "flatten" it once more or just leave it as it is because it already is flat?

    Hope you understand my question..
     
  2. Ed Fuqua

    Ed Fuqua

    Dec 13, 1999
    NYC
    Chuck Sher publishes my book, WALKING BASSICS:The Fundamentals of Jazz Bass Playing.
    If you have a key, write it out over and over

    Bb C D Eb F G A Bb C D Eb F G A Bb C D Eb F G A Bb


    Now pick the 7th degree of the scale
    A
    now pick a note that's the 3rd degree away
    A Bb C
    then pick another note that's the third degree away
    C D Eb
    then pick another note a 3rd degree away
    Eb F G

    So whadya got? A C Eb G = Aminor 7 flat 5

    I don't know where you're getting alla this "flatting" from...

    You ALWAYS ALWAYS ALWAYS use scale degrees present in the key signature, you don't need to add accidentals to get diatonic chords.

    The other way to look at it is building the chord from it's nomenclature = A minor 7 flat 5

    so you need an A minor triad = A C E
    you need the dominant 7 = A C E G
    and then you need the flat 5 = A C Eb G

    Clearer? You want to do an Bb-7b5 for me?
     
  3. Feda

    Feda Screwed up pitch

    Jan 12, 2004
    Bergen, Norway
    Can it be Bb-Db-E-Ab?

    Thanks for explaining!
     
  4. Tash

    Tash

    Feb 13, 2005
    Bel Air Maryland
    One technical error with this: there is no such interval as a "dominant 7". You are using a Minor 7th interval (1 whole step below the octave or root of the chord). A dominant 7 is a type of chord, specifically a Major triad with a minor 7 added. its called the Dominant 7 because it only occurs naturally on the dominant (5th) pitch of the major scale.

    Also the chord you are building is called a a half-diminished 7th chord, because it contains a diminished triad (root, minor 3rd and diminished, or flat 5th) with a minor 7th added. A fully diminished 7th chord would have a diminished 7th instead (and is composed entirely of minor 3rds).
     
  5. Suckbird

    Suckbird Banned

    May 4, 2004
    Sweden
    Ow, now i see how bad my theory is.

    Never heard of a Amin7b5 before... :bag:
     
  6. Ed Fuqua

    Ed Fuqua

    Dec 13, 1999
    NYC
    Chuck Sher publishes my book, WALKING BASSICS:The Fundamentals of Jazz Bass Playing.
    Almost. You want to remember about enharmonic spelling. The fifth degree of some kind of B chord is going to be some kind of F. B C D E F, right?

    So enharmonically, Fb is the same note as E and is some kind of F which will be the 5th degree.

    Half diminished and minor7b5 are interchangeable terms. Half diminished didn't even come into the vocabulary until mid 20th century.
     
  7. Tash

    Tash

    Feb 13, 2005
    Bel Air Maryland
    I really haven't either. Normally this chord is called a half-diminshed 7 as I explained above. I think the m7b5 name is more common in Jazz circles where chords are often refered to by their component intervals. This is probably due to the popularity of chords with added/altered tones in Jazz.
     
  8. Feda

    Feda Screwed up pitch

    Jan 12, 2004
    Bergen, Norway
     
  9. Richard Lindsey

    Richard Lindsey

    Mar 25, 2000
    Metro NYC
    IME m7b5 is more common than half-diminished 7--I wouldn't say the latter is "normal"--but there's absolutely no disagreement that they refer to the same thing.
     
  10. my old theory teacher used to go red and foam at the mouth if you ever said "half-dimished". he was adamant that it was always a m7b5, never half diminished. guess whatever works huh?

    btw- what is the notational symbol for half-diminished?
     
  11. Richard Lindsey

    Richard Lindsey

    Mar 25, 2000
    Metro NYC
    A circle with a slash through it.
     
  12. Tash

    Tash

    Feb 13, 2005
    Bel Air Maryland
    A circle, by the way, is the symbol for a fully diminished 7...get it, line through it, half, no line, full.... ;)

    Question: when you are labeling chords by interval collection (m7b5, Dom7b9, etc.) what's the convention for labeling the various inversions? "Dominant 7, Flat 9 four three" is a lot more clumsy on the tounge than "Five-four-three, flat 9".
     
  13. Richard Lindsey

    Richard Lindsey

    Mar 25, 2000
    Metro NYC
    Technically, as I learned it anyway, the circle should mean a diminished *triad*--1 b3 b5--rather than a diminished 7. So Ao would be A C Eb, and Ao7 would be A C Eb Gbb. Though the circle alone is not infrequently used for dim7 in my experience. So the half-diminished 7 would be slash-o 7. Though again, I've seen the slash-o by itself for that chord.

    As far as the inversions go, I forget what the technically most correct way might be--I probably did know it once!--but what I always see, and what seems easiest to me, is just to have the name of the chord, followed by a slash and the name of the desired bass note.
     
  14. Classical_Thump

    Classical_Thump

    Jan 26, 2005
    Well the inversion is listen as one or two numbers just on the left hand side of the cord. The most common are triads in first inversion (ex Amaj 6) or say a seventh chord in first inversion (Amaj7 65)- now the five would be under the six, sort of looking like a fraction but without a the bar between them. There are numbers like this for all inversions but I dont have time to type em all out now
     
  15. Tash

    Tash

    Feb 13, 2005
    Bel Air Maryland
    Chord inversion names:

    First inversion triad (third in bass): ChordName6
    Second inverstion triad(fifth in bass): ChordName64
    First inversion seventh (third in bass): ChordName65
    Second inverstion seventh(fifth in bass): ChordName43
    Third inversion seventh(seventh in bass): ChordName42

    All refer to the intervals above the lowest note (not the root note).