Scale Theory Roundup

Discussion in 'General Instruction [BG]' started by danqi, Feb 15, 2002.

  1. danqi


    May 21, 2001
    This is supposed to be a compilation of my current knowledge of basic scale related music theory. I am writing this down so you can correct me and I can be sure to be on the right track. Also, this may help some beginners who are just getting into this. I know it would have helped me a couple of weeks ago.

    1) Every scale consists of (is) a specific pattern of intervals. E.g. the major scale is wwswwws (w=whole tone, s=semi-tone)
    2) You can start that pattern on different notes to get different scales of the same family. If you start the pattern from above on C you would get the C Maj scale, if you start it on A, it would be the A Maj scale.
    3) The nice thing is: since the intervalic pattern stays the same, the pattern you play on the fingerboard also stays the same. You just need to move it around.
    4) The C Maj scale consists of different notes than the A Maj scale (or any other), it is the pattern that stays the same.
    5) You can take the notes of the C Maj scale (CDEFGABc) and play them at different starting notes. E.g. starting on D: DEFGABCd
    6) This is called a mode. In this case it is a mode of the C Maj scale.
    7) When you play a mode the notes are the same as in the original scale but the intervalic pattern is different (compare to 4).
    8) You can move the new pattern of the mode around on the fretboard, too. So you can also play the pattern you get by playing the mode starting on D starting on A. This would give you another scale than the mode starting on A.
    9) Since the Maj scale (or any other scale) gives you different notes when played on different positions (root notes), it has different modes for every root note. This means a C Maj scale has different modes than a A Maj scale.
    10) There are 12 different pitches (notes). That means there are 12 different maj scales, each with 7 different modes that can be played in 12 different positions. Because of that you can derrive 1008 scales from the major scale!!!:eek: (I must have gotten something wrong here:D )

    Chord stuff:
    11) There are different formulas to derrive major and minor chords from the major scale. You don't use the major scale to build major chords and the minor scale to build minor chords, because the minor scale is just a mode of the major scale.
    12) If you want to play something over a chord played by the guitar player (for example) using the major scale, you have 3 choices (let's say you want to play over E): You can play the E maj scale, or you can play the mode starting on E, or you can play any other mode and move it so its root is E.

    Question: Can you derrive chords off of the modes of the major scale using the same formulas(1-3-5, etc)?

    Well, I hope I got it all right. Maybe this even helps someone.

    Thanks to all you guys who provided me with this information and helpfull links, especially Jazzbo.

    Have a nice day,
  2. eli

    eli Mad showoff 7-stringer and Wish lover Supporting Member

    Dec 12, 1999
    NW suburban Chicago
    Item # 10: Not quite. There are only seven major-scale modes and 12 notes, so there are only 84 modal scales. Not quite so much practicing to do. :cool:

    But major-scale modes are not the only way to play. There are lots of scales that aren't modal. Melodic minor is one great example: going UP, you play 1,2,b3,4,5,6,7,8, but coming down you play 8,b7,b6,5,4,b3,2,1. Also, the blues scale is 1,2,b3,3,4,b5,5,6,b7,8. More than seven notes! More expressive, too.
  3. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator

    Oct 19, 2000
    Louisville, KY


    Most of your scale stuff looks pretty good. ELI WHITNEY did a good job of saving you some practice time on your modes, but your CHORD STUFF could use a little work.

    While you're right that the "1-3-5" formula is one way to derive chords from a scale, the big picture is a bit more complicated than that. While I'm sure that HASBRO touched on this in his chord thread, a little review might help:

    Think of each (common: Major or minor) scale as having seven different degrees, and number them from 1 to 7, with number 8 being an octave repeat of number one. Once you have done this, apply the 1-3-5 pattern to each note of the scale (i.e. - 1-3-5, 2-4-6, 3-5-7, etc), and you'll end up with seven triads - one built on each note of the scale. If you do this with C Major, the chords come out:

    CMa, Dmi, Emi, Fma, Gma, Ami, Bdim (diminished)

    Most theory books use Roman Numerals to refer to chords, and many use large and small RN's to designate chord quality. By using this system, you discover that for all Major scales, there is a set pattern of chord qualities. (Uppercase RN's designate Major, Lowercase designates minor)

    Key of: CMA....FMA...etc....

    Once you start to think of the Roman numerals, all you have to do is be able to spell a scale to know what harmonies to expect to find "inside" that key. Did that make sense?

    Hope this helps.

  4. danqi


    May 21, 2001
    But isn't it right that those 84 modal scales can again be played in 12 different positions just like the major scale in the first place? 12 x 7 x 12 = 1008 :cool: ;)

    Well, aha,...:confused: Up?Down?:confused:

    This would be exactly the same as applying the 1-3-5 pattern to every mode of the major scale, wouldn't it? Doing that I should come up with the same chords, I think.
    But how do I know which chords are minor, which are Major, and which are diminished?

    And what would happen if I would apply your approach (of applying the pattern to every note (2-4-6, 3-5-7, etc)) to every mode?
    Would that give me a whole lot of different chords?

    By the way: the minor scale is also just a mode of the major, right?

    Everything but this last sentence.
  5. eli

    eli Mad showoff 7-stringer and Wish lover Supporting Member

    Dec 12, 1999
    NW suburban Chicago
    In melodic minor, when you're playing ascending notes in a row, you play the 6 and 7 raised -- that is, that same as in the major scale. But when the notes are descending, you play the notes lowered, as in the natural minor scale. And yes, the natural minor scale is indeed a mode of the major scale. Aeolian, IIRC.
  6. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator

    Oct 19, 2000
    Louisville, KY
    All I meant by that was that if you know how to spell a major scale and number it from 1 to 7, and you know the pattern of Major and minor chords that occur in every major key (as designated by the Roman Numerals), then all you have to do is apply the roman numerals to the scale to figure out what chords are "from" that key.

    In any Major Key:

    I is Major
    ii is minor
    iii is minor
    IV is Major
    V is major
    vi is minor
    vii is diminished

    Apply the roman numerals to the scale degrees 1-7 of any major key, and voila! have the chords from "inside" that key.


    P.S. - I see that ELI and I seem to have cross posted on some of this stuff. No harm, no foul intended. :cool:
  7. danqi


    May 21, 2001
    Thank you so much!
    Now I think I am getting "the big picture" of it. Well, at least of this basic stuff. I could have REALLY confused myself if you had not helped me out. The same is true for that other post of mine (about key sign.).
  8. jazzbo


    Aug 25, 2000
    San Francisco, CA
    I miss all the good threads. Try not to start interesting threads on days I can't get to the computer. Okay guys?!