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Help Needed: Harmonizing a Scale

Discussion in 'General Instruction [BG]' started by degroove, Aug 24, 2004.


  1. degroove

    degroove

    Jun 5, 2002
    Wilmington, DE
    OK, my bass instructor first harmonized the G Major scale by adding 7ths to the triads. Here is what he provided:

    I G Major 7 G, B, D, F#
    II A Minor 7 A, C, E, G
    III B Minor 7 B, D, F#, A
    IV C Major 7 C, E, G, B
    V D 7 D, F#, A, C
    VI E Minor 7 E, G, B, D
    VII F#m7b5 F#, A, C, E

    These are basically all of the seventh arrpeggios in G Major. I am supposed to come up with the same for C Major. Here is what i have so far, but need help..

    I C Major 7 C, E, G, B
    II D Minor 7 D, F, A, C
    III E Minor 7 E, G, B, D
    IV F Major 7 F, A, C, E
    V G 7 ? G, B, D, ?(
    VI A Minor 7 A, C, E, ? (F)
    VII B minor b5 B,

    I am confused as to how to add the seventh. I know the basic rules on sevenths:
    Major Triad + Minor 7th = Dominant 7th
    Major Triad + Major 7th = Major 7th
    Minor Triad + Minor 7th = Minor 7th
    Dimished Triad + Minor 7th = Half Diminished 7th
    Diminished Triad + Diminished 7th = Fully Diminished

    My questions pertain to his use of roman numeral which does not seem correct unless he was just using them as a way to number them in a non roman numerical classificaiton method.

    My other question is Where does the 7th come from: The C major scale or the scale of the chord? The confusion for me comes from not thinking I can use sharps or flats due to the C scale being the original scale...

    Can anyone help me??

    Thanks! Matt ;)
     
  2. Boplicity

    Boplicity Supporting Member

    This is tough to explain and I call on any body else who can explain it better to help out.

    A major scale has scale tones which are named, but it also has scale degrees. In C major, the scale tones are in order:

    C D E F G A B C
    1 2 3 4 5 6 7 8 (or 1)

    The numbers under the scale tone names are the degree of the scale. Thus G is the fifth degree of the C major scale and
    B is the seventh degree of the C major scale.

    When you "harmonize" a major scale, you take each degree of the scale and find the chords that eminate from each degree. Thye can be triads or, as your teacher showed you, seventh chords.

    To harmonize the scale, you learn that each degree of the scale has another name...the name of the type of chord that comes from that scale degree. Thus:

    I ii iii IV V vi viimflat 5

    C Dm Em F G Am Bmflat 5

    Those are triads.

    If you make seventh cords from the scale degrees, you get:

    I Ma7 iim7 iiim7 IVMa7 V7 vim7 viim 7flat5

    C Ma7 Dm7 Em7 FMa7 G7 Am7 Bm7 flat 5


    Now to attempt to further explain your question, you wonder how to determine that seventh degree in each of the above styles of chords.

    Each chord has a formula, including seventh chords. You have four chord types here, major seven, minor seven, dominant seventh (also just called seventh) and minor seven flat five. These are the formulas:

    Major 7: Root, 3, 5, 7

    Minor 7: Root, 3, 5, flat 7

    Dominant 7: Root, 3, 5, flat 7

    Minor 7 Flat 5: Root, flat 3, flat 5, flat 7

    You ask where does the seventh come from? It comes from the seventh degree of the chord in question. Thus the seventh degree of an A minor chord will not be the same as the seventh degree in a B minor chord. Why? Because one starts counting scale degrees from the root of the chord, so seven notes up from A, will not be the same as seven notes up from B.

    As an example C major has these degrees. 1=C, 2=D, 3=E, 4=F, 5=G, 6=A, 7=B. The formula for a C major 7 chord is root(or 1), 3, 5, 7, so the tone names are C, E, G, B.

    The Roman numerals you refer to show the scale degrees of the key which in turn indicates the type of chord. Using Roman numerals makes it super easy to transpose keys ( or change keys) because chord progressions in songs are often given using a kind of short hand, such as I, IV, V, meaning the first, fourth and fifth chord of a key. So if you change keys, all you have to do...say to change from the key of G to the key of C when both are using a I, IV, V chord progression is know what those chords are in the new key.

    I hope that is some help.
     
  3. Slot

    Slot

    Oct 17, 2003
    Sydney - The Shire
    An easy way to think of 7ths is this

    A minor 7th is always a tone below the root

    A major 7th is always a semitone below the root



    So once you're familiar with the triads, all you have to do is use that rule to add the 7th


    Also, chord construction of diatonic 7th chords follows the simple pattern of, every second note in the scale equals a chord tone(1, 3, 5, 7). Look at this

    Chord I, Cmaj7

    CdEfGaBcdefgabc

    So chord II, Dmin7, would be

    cDeFgAbCdefgabc

    Chord III, Emin7

    cdEfGaBcDefgabc

    etc etc

    This is the same for every major scale. So all you have to do is write out the scale, then circle every second note to construct the 7th chords.

    Hope this helps
     
  4. degroove

    degroove

    Jun 5, 2002
    Wilmington, DE
    Yes. The rules and your explanation are very helpful. I am going to try the E Major scale now...

    E, F#, G#, A, B, C#, D#

    I E, G#, B, D#
    ii F#, A, C#, E
    iii G#, B, D#, F#
    IV A, C#, E, G#
    V B, D#, F#, A
    vi C#, E, G#, B
    vii Dim D#, F#, Ab, C#

    Does this look right??
     
  5. Fill-In

    Fill-In

    Jul 24, 2004
    whoa---I think that 'A' should be natural in your vii chord
     
  6. Fill-In

    Fill-In

    Jul 24, 2004
    or were you even asking us???
     
  7. stephanie

    stephanie

    Nov 14, 2000
    Scranton, PA
    If you were to play me those arpeggios with me not looking at them written I would say you were correct, however, you asked if they looked right...

    Let's take a look at the Ab in your vii chord. Now Ab and G# are enharmonics, meaning they sound the same but are spelled differently. You want to use the note that is in your key however, so you would use the G#. D#m7b5 = D# F# G# C#.

    Your teacher probably also wants you to write out the actual chord names before spelling it. (EX: I - Emaj7 = E G# B D#), as you showed in your initial post.
     
  8. Slot

    Slot

    Oct 17, 2003
    Sydney - The Shire
    Hate to be pedantic, but D#min7b5 is actually, D# F# A C#
     
  9. stephanie

    stephanie

    Nov 14, 2000
    Scranton, PA
    Oops heh, where's my mind tonight? Thanks for pointing that out. Sorry. :oops:
     
  10. degroove

    degroove

    Jun 5, 2002
    Wilmington, DE
    Noted. Thanks!

    Cool.

    Thanks, you all, I feel I am really getting this. I appreciate you looking at my work ... ;) :hyper: