modal theory question

Discussion in 'General Instruction [BG]' started by LiquidMidnight, Jul 11, 2002.

  1. LiquidMidnight


    Dec 25, 2000
    Hey cats, in my ever endless pursuit of musical knowledge, ( ;) ) a question about modes has arrived. It's not so much a "How do You" kind of question, but more of a "Why is it" type.

    I understand that if you begin a song in a certain mode, (for example D dorian) all of the other chords (for the most part) should base themselves around that starting mode. Like let's say you play an E after that D, that E should be based in phyrgian, a C in Ionian and so forth. For a lot of musical styles such as Classical that holds true, but it seems like the more popular styles of music (i.e. Rock, Country, Blues, Pop) do not follow that rule. I've noticed that for most part, each chord in a Blues progression is treated as though it is based out of mixolydian. My question is, why is that? I've been playing music like that for years, and I just always knew to play each major chord as though it was out of mixolydian, but I never understood why. (when it's been pounded in our head to follow modes in chord progressions)
  2. Bruce Lindfield

    Bruce Lindfield Unprofessional TalkBass Contributor Gold Supporting Member

    Well this is not really a question about modes as such but rather which scale goes with which type of chord.

    So a blues progression is all mixolydian, because every chord in the progression is a Dominant 7th chord - of course there are alternatives to mixolydian. But I think the whole question is a bit "mixed up"! ;)

    But the point is that the chords aren't straight Major as they have a flattened 7th.

    Most other songs apart from the blues wouldn't be all dominant 7ths - they would have some major 7ths or maybe some minor chords or diminished...etc.

    Jazz players re-harmonise the Blues with other chords for example.

    I think you need to start from the point that each chord is taken on its merits and by looking at its type and its function in the harmony then you decide which scale(s) you can use - modes are sort of irelevant, although it can help you to think of say a minor scale as just another mode of a major scale - but in this case it's probably more confusing!
  3. LiquidMidnight


    Dec 25, 2000
    I understand what you mean Bruce, though that kind of contradicts what we've been taught about harmonizing scales with chords. It's all well and good as long as the guitar/piano/horn section ect. are playing the extra notes that goes beyond a triad and signifies the chord extensions, but a lot of the times, only a triad is being played, while the bass implies the chordal extension in it's run. A simple example, but one that gets my point across, is when a guitar is playing the standard Rock n' Roll Boogie riff (not sure if it has a special name, in tab it would look like this)

    E---0--0---0--0- ect.

    (excuse my crap tab)

    While the bass would be playing a jitterbug style line with flatted 7ths. (it would go E, G#, B, C#, D, C#, B, G#, all using quarter notes, it would then change to the same forumula depending on the chord) Even though the guitar isn't playing the flatted 7th, I just know that it's there simply because I've played those type of songs, and have heard/watched other bassist play them, that I know it will sound right. But if I never played a song like that, I wouldn't know about the implied flatted 7th.

    Sorry Bruce, I kind of went out in left field with my rant. I'm just trying to figure out the theory to a lot of crap I do but don't understand why. Well, the Simpson's are on, so I better get going. Thanks for answering my question. :)
  4. jazzbo


    Aug 25, 2000
    San Francisco, CA
    Which is why I prefer jazz blues. For one, the turnarounds are so much more interesting harmonically, but they don't have that stagnant, ostinato, bass line feel. I'm getting to the point where I can't even listen to BB King, Koko Taylor, or the like. How 'bout some Delta Blues, some Muddy Waters, Keb Mo?

    So you're digging along in the blues, and you know that it's a G major blues, and you're getting this crap:

    G7 / C7 / G7 / G7
    C7 / C7 / G7 / G7
    D7 / C7 / G7 / G7

    So, you're thinking, "Hey, I know Dom7 chords can have Mixolydian modes used over them for a good harmony!" And, yeah, you're right, but notice how you said "can have", not "must have." For all intense purposes, this song is in G major, isn't it? But, that G7 right from the bat might lead you to believe C Ionian is the overall tonality. But how can that be, cause there's a flat 7 in that C chord there, so it must be F major. Nope, can't be that either, cause the Bb doesn't work in the G7, although it does work in the C7! Confused yet?

    Ahh, the glory of popular blues. You see, they're using chromaticisms. So, you can't look at this as Gmixolydian, Cmixolydian, Dmixolydian. But, you CAN look at it as G major, with a flatted 7. What's the difference? Well, just remember that when you get to the 4th and 5th, you'll have to play those as Dom chords too. Bruce's point, about honoring the overall tonality of the song, is going to be more important than thinking "modally." Let me give you an example.

    So you're playing this bassline, chugging away 100% modally, and the guitarist is wanking his 64 chorus solo, right? All is good. The guitarist is probably wanking on minor pentatonic with a raised 4, (and we all know that blues guitarists generally completely ignore harmony), which is:

    G Bb C C# D F


    Crap! Right away we've got a problem with that G7, (G-B-D-F), you're playing. What's up with that "B" when he's wanking on "Bb"? And you know how guitarists rely on their thirds. But, you might be able to get away with that with all the pitch bending that guitarists do in blues. Okay, you're kind of safe. Well, what happens when you get to your C mixolydian. CEGBb. Hey, it works. Except that pesky E might be interfering with that F that the guitarist is using to resolve back to G. Now when you get to D7, that DF#AC is just causing all sorts of problems.

    See, you've got to pay attention to the overall tonality of the piece. Each chord isn't necessarily Mixolydian in blues, but rather it's the I-IV-V of the overall key, with some chromaticisms.
  5. Pacman

    Pacman Layin' Down Time Staff Member Gold Supporting Member

    Apr 1, 2000
    Omaha, Nebraska
    Endorsing Artist: Roscoe Guitars, DR Strings, Aguilar Amplification
    Well, that's not true at all. Modal harmony isn't 'based' on anything really. It's very much about the 'sounds' you get with certain harmonies, and not worrying about how you put them together. Take for instance one of the most common modal tunes, "so what". It's 16 bars of a modal "sound" followed by 8 bars of that same modal sound, up a half step, and then 8 more bars of the original chord. There's no cadences, no V chords, the two chords are unrelated. The framework miles came up with was a framework to blow solos, to create an environment where the soloist created the tension and release, not the changes.

    You don't have to base chords on anything related to the other chords.
  6. LiquidMidnight


    Dec 25, 2000
    Thanks for the info guys, that helped clear a lot of things up.