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  1. #1

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    Hi,

    I’m new to Jazz and to this site, so apologies if I could have searched for this.

    I’m trying to understand the Roman numeral chord descriptions for diatonic chords. If I take A natural minor as an example we have Am7 on the first scale degree and Dm7 on the fourth. However, if I look at the “recipe” I see that the first degree is Im7 and the fourth is ivm7.

    Why does the first degree have a capital I and the fourth a lower case iv?

    Also I see the 7th degree as bVII7. Is it bVII because it is a major chord built on the flat 7th degree? Ie 2 semitones rather than 1 below the tonic?

    Many thanks for the help!

    John

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    The Jazz Guitar Chord Dictionary
     
  3. #2

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  4. #3

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    Quote Originally Posted by jforgan View Post
    Why does the first degree have a capital I and the fourth a lower case iv?
    It shouldn't have. Major is capital/upper case, minor is lower case.

    Also I see the 7th degree as bVII7. Is it bVII because it is a major chord built on the flat 7th degree? Ie 2 semitones rather than 1 below the tonic?
    If it's the 7th degree of the major scale then it would not be a dominant chord. It would be a half-diminished (like Bm7b5 in C major). Being minor it would be vii.

    In the minor (A minor here) the 7th chord is a dominant, which is G7. That would be VII. It's not generally written as b7.

    However, in describing the notes of a dominant chord, the 7th note is often called a b7 because the intervals are based on the root's major scale.

    In G major the 7th is F#, so in G7 it would become the b7.

    Another quick random example to make the point. Take a Dm6 chord.

    The D major scale is D E F# G A B C#. The notes of Dm6 are D F A B. So, counting and comparing with D major, the intervals would be 1 b3 5 6.

    That's the way I like to do it because I find it easy. Others like to describe intervals by the number of semitones between notes. I'll let them do that because it confuses me :-)

    Like there are 4 steps to a major 3rd and 7 steps to a perfect 5th, etc. No thanks!

  5. #4

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    Quote Originally Posted by jforgan View Post
    Hi,

    I’m new to Jazz and to this site, so apologies if I could have searched for this.

    I’m trying to understand the Roman numeral chord descriptions for diatonic chords. If I take A natural minor as an example we have Am7 on the first scale degree and Dm7 on the fourth. However, if I look at the “recipe” I see that the first degree is Im7 and the fourth is ivm7.

    Why does the first degree have a capital I and the fourth a lower case iv?
    Hi,
    Roman Numeral analysis is used in western classical music and is not specific to Jazz. Roman numerals are used when analyzing harmonic sequence as well as in the broader aspect of Function analysis. There are differences in European vs American tradition.

    Sometimes all triads are represented by upper case Roman numerals, followed by a symbol to indicate an attribute (e.g. "m" for minor or "ø" for half-diminished, "7" for a flattened seventh).

    It's practical to differentiate notation for Major and minor scale:

    Major scale traditional notation (minor chords in lower case)
    I ii iii IV V vi viio

    Major scale alternative notation (all chords in capital letters)
    I II III IV V VI VII

    Minor scale traditional notation (minor chords in lower case)
    i iio bIII iv V bVI bVII viio

    Minor scale alternative notation (all chords in lower case)
    I ii iii iv v vi vii

    The function of each note is different depending on Mode, e.g it's "bVII" in Dorian, but "bvii" in Phrygian.

    Quote Originally Posted by jforgan View Post
    Also I see the 7th degree as bVII7. Is it bVII because it is a major chord built on the flat 7th degree? Ie 2 semitones rather than 1 below the tonic?

    Many thanks for the help!

    John
    In minor scale the bVII is the "subtonic", a flattened seventh, a whole step below the "tonic". (viio is the "leading tone" a semi step below the tonic.)

    VII refers to the seventh note in the scale, bVII to a flattened seventh in the scale. In "bVII7" the "7" referes to the flattened seventh note (b7) in in the bVII-chord. It happens to be redundant, but I don't think it can be misinterpreted.
    Last edited by JCat; 03-11-2019 at 03:49 AM.

  6. #5

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    Minor scale alternative notation (all chords in lower case)
    I ii iii iv v vi vii
    Well, that'll be confusing, won't it? :-)

  7. #6

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    Quote Originally Posted by ragman1 View Post
    Well, that'll be confusing, won't it? :-)
    Doesn't have to be, like when used together with the symbol "m" to indicate a minor chord in the minor scale.
    It's no more confusing than when capital letters are used both for minor and major chords, which appears to be rather common. It's also common to borrow chords from the respective scale (chords that would be minor according to the scale is in fact major and vice versa.) After all, the "m"-symbol is convenient.
    Last edited by JCat; 03-11-2019 at 08:21 AM.

  8. #7
    Great answers, thanks very much.

    I should really have posted this earlier, but the minor scale diatonic chords formula I’m talking about is

    Im7-iim7b5-bIIImaj7-ivm7-vm7-bVImaj7-bVII7 from the 30 Day Starter course

    So my questions were why “Im7” and not “im7”, and why are the 3rd, 6th and 7th degrees prefixed with ‘b’?

    My assumption was that Im7 is a mistake and that the ‘b’s are saying to build the chord on the flattened interval wrt. to the Major scale

    But you know what they say about assumptions!

  9. #8

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    Quote Originally Posted by jforgan View Post

    why “Im7” and not “im7”
    It is a mistake. The generally-used notation is i for minor. I suspect some editor thought 'capital letter at the start of a sentence' or something!

    why are the 3rd, 6th and 7th degrees prefixed with ‘b’?
    My assumption was that Im7 is a mistake and that the ‘b’s are saying to build the chord on the flattened interval wrt. to the Major scale
    You've got it. Not that you need to spell the word major with a capital M :-)

    Im7-iim7b5-bIIImaj7-ivm7-vm7-bVImaj7-bVII7
    CDEFGAB

    Cm7 - Dm7b5 - EbM7 - Fm7 - Gm7 - AbM7 - Bb7

    So that's the C natural minor scale. Et voila :-)

  10. #9

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    Quote Originally Posted by jforgan View Post
    the minor scale diatonic chords formula I’m talking about is
    Im7-iim7b5-bIIImaj7-ivm7-vm7-bVImaj7-bVII7 from the 30 Day Starter course
    What 30 day starter course?

  11. #10
    Quote Originally Posted by cosmic gumbo View Post
    What 30 day starter course?

    30 Days To Better Jazz Guitar

  12. #11

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    Quote Originally Posted by jforgan View Post
    So this is actually an ebook by Matt Warnock from the jazz guitar forum ebook store.


    Here's some information that's in question from the book:



    How To Analyze a Jazz Standard Using Roman Numerals | Music Theory

    I'm thinking the capital I in Im7 is to reference it as tonic, I can see that logic, whether I agree or not. The 3rd degree of the natural minor scale (aeolian) is bIII7 because it is a major 7 chord built on an interval a minor 3rd from the tonic, and so on for the other degrees of the scale. It is denoting the proper intervals.

  13. #12

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    If one thinks of Im7 as starting with the basis of major intervals subject to alteration (starting all chord type descriptions with the major chord type and adjusting it to the particular chord type you wish to represent), then applying the adjustment or operation of making it minor by adding the "m" to the major basis indicated by "I" seem tedious and unnecessary. It is the final form after these operations that we are really interested in representing, so ii7 is a clearer way to show minor seventh.


    The Roman numeral for "one" is what identifies the chord's root as the tonic of the basis (harmonized) scale's degrees. The choice of upper or lower case Roman numeral is a clear way to distinguish the quality of the chord as major or minor, meaning that the upper case indicates the third of the chord is a major third with respect to the root of the chord, and lower case indicates the third of the chord is a minor third with respect to the root of the chord.


    Parsing Im7 is unclear if one interprets the "I" to indicate the third of the chord as a major third with respect to the root of this chord. Then the "m" here might be thought to apply strictly to the seventh and not the third because of the upper case "I", and since this is jazz, it might be mistaken for another way to show a simple dominant seventh chord.

    Or one might interpret the Im7 as starting with the basis of major and applying a transformation via the "m" to the third to become minor, with the seventh understood to be a dominant seventh (flatted but not indicated as so). But then what about iim7b5 ?


    If you start with major as the basis from which to deviate... well already that is not what is happening here with iim7b5. It is already indicating minor with lower case "ii" as the scale degree numeration of the chord's root with respect to the basis major harmonized scale's degrees tonic'ed from its "one" (so iim7b5 is skipping the step of starting with an initial setting of "major" from which to proceed construction of the two chord), then invoking a redundant operation of minor with "m"... that's not even a double negative! That's lowering the already lowered third via the "ii" a second semitone down via the "m", so the chord representation shows two operations to flatten the third. That is, unless you restrict the "ii" application to only the third and allocate the "m" application to the 7... but we already consider "7" to mean flat seventh, as the "norm" for the seventh (despite the norm for the seventh of the basis major scale being the major (unflatted) seventh). So flatting the "7" which is already flatted would push it down to a sixth.


    How would you parse iim7b5 ?

    - minor third minor seventh flat five?
    - double minor third dominant seventh flat five?
    - sus two flat five?
    - minor sus two flat five no third?
    - double diminished third flat five?
    - minor sixth flat five?


    ii7b5 is clearer.

    In a recent thread I suggested that a way to save jazz might be to stop teaching it. I did not even consider another way, which would be a counter operation of teaching it in such a way so inconsistent, incoherent, unintelligible, and intractable that rational students would be unable to discern even a firm enough foundation to consider performing.
    "Bent my ear to hear the tune and closed my eyes to see."

  14. #13

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    So are we at the point now where we shouldn't recommend the forum's lessons material?? That's kinda what it sounds like...

    How To Analyze a Jazz Standard Using Roman Numerals | Music Theory

  15. #14

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    Im7
    Well, I suppose if you put the 'm' in it's more or less clear that it's minor.