Monday, August 16, 2010

Some Points on the Mixolydian Mode

Q: Hi Chris, I just checked out your revision of the mixolydian lesson on your site and the new video. I really liked the sounds you get with mixolydian especially in the Blues you played. I just have a few questions.

Q1. Why is it that you can play a G minor pentatonic (or major pentatonic) over the whole 12 bar progression, but have to switch mixolydian modes for each of the three chords?

A: Well, both the minor and major pentatonic scales will (for the most part) work over the whole progression because of their simplicity. I suppose that is why using one or both of them is a popular approach rather than using a separate mixolydian scale over each chord. Even though you can technically use both a minor and major pentatonic scale over a Blues, not all the notes work well over each of the chords. For example, take a look at the G minor pentatonic scale: G-Bb-C-D-F. And remembering that chord tones sound the best over each of the chords you play over, look at the scale compared to each chord in a G Blues:

Here is the G minor pentatonic scale again: G-Bb-C-D-F

G7 (G-B-D-F): The scale has three chord tones, the root (G), 5th (D) and b7th (F). C is sort of lame as it is a 4th and the chord isn't a 7sus4 chord and the Bb needs to be bent up the the major 3rd to sound right against the G7 chord. But overall, your chances of hitting a good note is pretty high.

C7 (C-E-G-Bb): The scale has three chord tones, the root (C), the 5th (G) and the b7th (Bb). Again pretty good hit/miss ratio against the IV chord.

D7 (D-F#-A-C): Two chord tones here. We have the root (D) and b7th (C). So we have to be a little more cautious using the scale over this chord.

But all in all, you have will have pretty good luck using the minor pentatonic scale over the Blues progression. You just need some sense and decent ears.

Now let's take a look at the G major pentatonic scale used over a G Blues progression. Here is the G major pentatonic scale: G-A-B-D-E

G7 (G-B-D-F): Three chord tones available, the root (G), 3rd (B) and 5th (D).

C7 (C-E-G-Bb): The scale has two chord tones, the 5th (G) and the 3rd (E). The biggest problem with this scale over the IV chord is that is has some downright lousy notes. The worst being the B note which is a major 7 to the C7 chord. If you play this note and hold it, you could probably make someone in the audience throw up. If you dare to play it, try bending it up to the root for good results.

D7 (D-F#-A-C): Two chord tones here as well. We get the root (D) and the 5th (A). The remaining three notes in the scale are not chord tones, but they aren't blatantly ugly (like the B note over the C7 chord) either.

Now on to the mixolydian scale. You can get pretty good results from using the G mixolydian scale over the whole thing. I mean, Blues harp players pretty much do exactly that to some extent. For example, a Blues harp player would use a C major harmonica over a G Blues and as you know from the lesson, the C major scale over a G7 chord is the G mixolydian mode.

Let's look at the G mixolydian scale over all three chords. Here is the G mixolydian scale: G-A-B-C-D-E-F.

G7 (G-B-D-F): We get every chord tone!! Bingo! If I have any advice for you here, beware of the 4th. It doesn't sound that hot over a G7 chord unless it is a 7sus4 chord, in that case it would sound pretty good but the 3rd would then have some problems.

C7 (C-E-G-Bb): Three chord tones, the root (C), the 3rd (E) and the 5th (G). Be very careful because once again, there is a B note in the scale which is the major 7th and will gross you out over a C7 chord if you hold it for any length of time.

D7 (D-F#-A-C): Three chord tones here, the root (D), the 5th (A) and the b7th (C). When the G mixolydian scale gets played over this chord, there is a minor 3rd (F) that you might want to bend up to the 3rd of the chord (F#).

All in all, the G mixolydian scale over the entire Blues progression isn't that bad of a choice but it leaves a lot to be desired, simple because of the difficulty in making the changes using it. But remember, using the corresponding mixolydian scale over each chord offers you the opportunity to get all the chord tones on all three dominant chords. 

I personally prefer to use the mixolydian mode over the IV chord, for example, C mixolydian over the C7 chord in a G Blues, while sticking to a combination of the minor and major pentatonic over the I and V chords (although I'm somewhat inclined to use the mixolydian scale over the I chord from time to time). There is a good reason for using mixolydian over the IV chord, you can see that the C mixolydian scale and G minor pentatonic scale are pretty close to the same, or at least we could say that there is a G minor pentatonic scale inside of the C mixolydian scale. See:

G minor pentatonic: G-Bb-C-D-F

C mixolydian: C-D-E-F-G-A-Bb

Therefore playing the G minor pentatonic scale over the G7 chord and simply expanding it to the C mixolydian scale for the C7 chord is a fairly simple thing to do (just add a E and A note). Some players like to play the C mixolydian mode over both the I and IV chords but I don't think that is a great choice (if you want to know why, there is another post here).

Q2: I can follow what you are playing somewhat on the video. But in certain places I'm not quite sure (especially over the C7 chord at around 14 minutes). Can you tell me where you start using the mixolydian scale or if there is something else going on?

A: Sure. I'll take a look and notate the times (keep in mind, when I say G minor pentatonic, I might be playing a major 3rd here and there):

10:48 - 11:10 - G minor pentatonic scale
11:11 - 11:19 - C mixolydian
11:20 - 11:22 - G minor pentatonic
11:23 - 11:28 - G mixolydian
11:29 - 11:46 - G minor pentatonic (with emphasis on an added A note for the D7 chord)
11:47 - 11:50 - G mixolydian
11:51 - 11:55 - C mixolydian
11:56 - 12:03 - G mixolydian
12:04 - 12:11 - C mixolydian
12:12 - 12:37 - G minor pentatonic
12:38 - 12:42 - G mixolydian
12:43 - 12:47 - G minor pentatonic 
12:48 - 12:55 - G mixolydian
12:56 - 13:06 - C mixolydian - 
13:07 - 13:16 - G minor pentatonic
13:17 - 13:21 - C Mixolydian
13:22 - 13:30 - G minor pentatonic
13:31 - 13:35 - G mixolydian
13:36 - 13:38 - C mixoldydian
13:39 - 13:47 - G mixolydian (the arpeggio thing you hear is basically the diatonic arpeggios ascending from Cmaj7 up to Amin7)
13:48 - 13:55 - C mixolydian 
13:56 - 14:05 - G minor pentatonic 
14:06 - 14:09 D mixolydian (something I usually don't do)
14:10 - 14:12 - C lydian dominant (Woops.. sorry, I cheated) 
14:13 - end - G minor pentatonic