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Why does this modulation work? C- to Ab-

Discussion in 'General Instruction [BG]' started by davecheng, Mar 13, 2010.


  1. Can you explain why this works?

    Take Cissy Strut. (For reference, I refer to parts in this video.)

    Play the main riff (0:25-0:45) in C-.

    Then, at the B section (0:46-1:06), change key to Ab-. Back to C- for the head.

    The sax guy I played with last night called this one out mid-song while he continued to blow over the change. It sounded great.

    But why does the C- to Ab- work? It's a weird interval. Ab is the 6 of C-. We played through the modulation without a pivot chord.

    Is there something special about modulating to the 6? As opposed to any other interval?
     
  2. onlyclave

    onlyclave

    Oct 28, 2005
    Seattle
    Not sure what you're talking about because in your John Mayer example they jam in Cmi for the entire tune.

    Are you saying that when you were playing it with the sax player he called Abma7 for the 'B' section? That would make more sense because Cmi (C Eb G) has a lot of common tones with Abma7 (Ab C Eb G) and it sounds cool because the root relationship between the two is a Maj 3rd, which is more of a neoclassical harmonic technique.
     
  3. My first reaction was this may be Cm instead of C major. Ab is the relative major of Cm.
     
  4. Slax

    Slax

    Nov 5, 2007
    Long Island, NY
    I thought Eb was the relative major to Cm...
     
  5. (Maybe my use of "-" above to denote minor was confusing?)

    I only posed the Mayer video above because I wanted an audible reference to what I call the head (or A) and B section of the tune. Yes, in that video, it's in Cm the entire time.

    The descending Cm pentatonic unison riff on bass typically ends on a G (that's the head or main riff I refer to above).

    And yes, in the video, they continue to the B section in Cm. But my example, transpose to Abm and play the riff in Abm (notes are Ab, Gb, Eb, Ab). I don't think this section is Imaj7, is it? I hear the key of Imin because the riff is based around the pentatonic minor of the I/root.

    For the head, modulate back to Cm.

    I guess I'm trying to figure out why these Cm and Abm riffs work harmonically.

    My first reaction was that the A-section riff (head) starts with a descending C- pentatonic, but ends on a G (for the guitar's Bbmaj/G Fmaj/G chords), which is only a semitone away (leading into?) the Ab of the B-section pentatonic riff transposed to Abm.

    I'm sorry if I'm not making any sense?

    (I have a knack for overthinking things. :()

    (Edit: This is a craptacular recording I made of the change. Done on a guitar, with mindless pentatonic noodling.)
     
  6. It is. I don't know why the poster above would've suggested that.
     
  7. VitaminC

    VitaminC

    Oct 4, 2008
    A minor = C major... he probably just got a bit confused or maybe it slipped his mind.
     
  8. Scott McC

    Scott McC

    May 13, 2006
    Toronto
    There is common tones between the two keys. Both keys can potentially have Eb, Bb, Ab, G, F and B within them. So, the notes not belonging to the key of the moment just sound a little quirky if used well.
     
  9. onlyclave

    onlyclave

    Oct 28, 2005
    Seattle
    They don't. Two keys a major third apart is a pretty remote modulation. 4 sharps, in fact. Abruptly changing from Cmi to Abmi with no pivot chord is a direct modulation. We're not as used to hearing that abrupt change and so it has a different sound than a modulation with a pivot chord. It sounds to me like something between a deceptive cadence and a neopolitan 6th chord.
     
  10. Eb is the major mediant to Cm
    Ab is the relative major to Cm according to all my charts.

    What am I missing?
     
  11. buddyro57

    buddyro57 me and PJ (living with the angels now)

    Apr 14, 2006
    Cedar Falls Iowa
    In classical music, going from c minor to ab minor would be thought of as a chromatic third relation- not that uncommon either, especially in mid-to-late 19th century literature. Strauss' Fruhling (no 1 of the Four Last Songs) begins with exactly this harmonic motion.
    I think it is exactly the freshness of it that makes it work; tonal logic sounds pretty tame compared to this stuff. Lastly, think of how far tonally you are with this motion- c minor (3 flats) all the way to Emaj (4 sharps). I am respelling ab minor as an enharmonic G# minor for convenience. But that is a hell of a long trip around the circle of fifths- that's why the motion is so striking (in my view).


    JS
     
  12. Relative Major/Minor are a Major 6th/Minor 3rd apart. think in Cmaj/Amin, from Cmaj, go up a major 6 or down a minor 3rd to find A (the relative minor). From Amin go up a minor 3rd or down a major 6th to find C (the relative major). Another way to think is Aeolian ↔ Ionian. In your example you're going from Aeolian ↔ Lydian, still a major chord, just the wrong one. :)

    Also check your cycle of 5ths/4ths - 3 flats (B E & A) give you the key of Ebmaj/Cmin (http://www.mariadewi.com/wordpress/wp-content/uploads/2009/02/circle-of-fifths.jpg as a quick ref.)
     
  13. Cool.

    It definitely sounded fresh to my ear, and that's what I was racking my brain trying to figure out why it worked.
     
  14. Pacman

    Pacman Layin' Down Time Staff Member Gold Supporting Member

    Apr 1, 2000
    Omaha, Nebraska
    Endorsing Artist: Roscoe Guitars, DR Strings, Aguilar Amplification
    Apparently, good charts.

    Eb is the relative major to C minor. Ab is the relative major to F minor.
     
  15. Maybe back things up a little here. IMO the initial premise is not right. That is, I don't think you're in C minor to begin with. Whenever I've heard or played the tune, the basic underlying chord is not Cm7, it's C7/9. Yes, of course the melody makes use of the minor 3 and can mostly be reduced to blues scale or minor pentatonic, but that's really no difference from what a lot of blues and rock does, namely play the minor 3 over a chord containing a major 3. Even in that Mayer clip, you can hear that the few times he hits chords when playing the melody, they're not minor 7th chords. So the harmony (such as it is) is really kind of major-ish. (To the extent that conventional major/minor even applies to this kind of stuff. I know, there's no leading tone, etc. All I really mean by major-ish is that the chords make use of major 3rds much of the time.)

    Second, if you're just playing the B riff a major third down, you're not really in Ab minor either. This suggests an Ab7/9 chord more than Abm7. So again, major-ish.

    From C major to Ab is more of a move than from C to F or G, but it's not a huge reach. One reason is that both contain the note C. Another is that Ab has some of the same notes as C minor (though, as has been pointed out, it's not the relative major of C minor, Eb is). And in fact Ab can occur "naturally" in C minor. So this means that going from C major to Ab major has a little of the feel of C major to C minor, which is not a huge jump.

    Don't get me wrong, you can get to Ab minor from C minor; it's just that that's not what's really happening here IMO.
     
  16. Well I did make them myself, so a little help getting them correct would be appreciated. I think my problem lies in the naming. Using i, iidim, III, iv, v, VI, VII for natural minor.

    Name........................Note
    i minor tonic ................C
    iidim super tonic...........D
    III major mediant........Eb
    iv minor subdominant....F
    v minor dominant.........G
    VI Major relative.........Ab
    VII Major sub tonic......Bb

    Appreciate getting back on the right track. I'm comfortable with upper case / lower case let's not go there.

    Thanks.
     
  17. Well, just in regard to remembering pairs of relative majors and minors, it's simpler than that. All you really have to do is remember is that from any minor chord, the relative major is an interval of a minor 3rd up (or a major 6th down). From any major chord, the relative minor is a minor 3rd down (or a major 6th up). Make sure you get the enharmonics right: for example, the relative major of Ab minor is Cb major, not B major. In practice, it doesn't always matter (enharmonic equivalences can help you with some screwy modulations), but for the purposes of understanding, it does.

    Analysis of the basic scales and their degrees will give you the same result, and they should indeed be studied so that you know WHY things come out that way. But just as a means of remembering, all you have to do is think in terms of intervals--that is, distances.

    Note that it's easy to confuse 1, 2, 3, etc. as names for scale degrees with 2nd, 3rd, 4th, etc. as names for intervals. Not the same thing, but as a result of our standard nomenclature, easy to mix up.
     
  18. The "VI Major Relative" bit is wrong, I thinks it's "VI Submediant" but not 100% about that.

    The simple way to find your relative maj/min is to use the 6th scale degree of the maj (to find the rel min) & the flat 3rd degree of the minor (to find the rel maj)

    A major 6th & a minor 3rd are inversions of each other. A really fool proof way to find the relative maj/min is to take the root of your major chord & go down 3 frets, to find the rel min, or take the root of your minor chord & go up 3 frets to find the root of the rel maj.
     
  19. Maybe the way you've organized the info is a tad confusing. The way you have it tends to stick descriptions of chords next to descriptions of notes. I would be inclined to think of the info in five categories. Maybe even as a 5-column table.

    1) Degree of scale: 1 (Let's go with C natural minor for now)
    2) Name of that degree: tonic
    3) Specific note (in C minor): C
    4) Quality of triad built on that degree: minor
    5) Roman numeral representing that chord: i

    1) Degree of scale: 2
    2) Name of that degree: supertonic
    3) Specific note (in C natural minor scale): D
    4) Quality of triad built on that degree: diminished
    5) Roman numeral representing that chord: ii(dim)

    1) Degree of scale: 3
    2) Name of that degree: mediant
    3) Specific note (in C natural minor scale): Eb
    4) Quality of triad built on that degree: major
    5) Roman numeral representing that chord: III

    And so forth. Note that upper- and lowercase Roman numerals represent chords here, not single notes.
     
  20. Yep, the 6 is the submediant.
     
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