# Quick theory question.

Discussion in 'General Instruction [BG]' started by tocoadog, Dec 10, 2005.

Apr 10, 2005
Say I'm playing in the key of Gmin (Relative Major Bb).

Quick down in dirty i-iv-v blues shuffle, with Gmin, Cmin, and Dmin.

Okay, so the key is Gmin, so I have as notes to play with...G, A, Bb, C, D, Eb, F, G (aelion). (i may have spelled that wrong..it's late )

Okay...so I'm playing:
i => G F G Bb A
iv => C Bb C Eb D
v => D C D F E

Okay, my question is, while playing the v chord, I'm playing an E note here, which is out of the Gmin chord. Now, why does this work, or seem to work?

I'm stumped. I for the life of me am trying to brainstorm in my ever-growing knowledge AND confusion of theory to figure out why this works, and I can't seem to find it. Maybe it doesn't work and my ears are deceiving me.

Also, could someone shed a little light on why in a minor key, the 5th is dominant (mixolydian).

And before anyone recommends a teacher, I have one, it's just I have soooo many questions when I play, 30 mins just doesn't cut it.

Thanks for any responses.

2. ### Alvaro Martín Gómez A.TalkBass' resident Bongo + cowbell player

Are you sure that the song has a Dm? For a V chord to have a dominant quality, it always should be major, no matter that the key center is minor, so your V chord should be a D7 (D-F#-A-C). I don't mean that the V minor doesn't exist, but it doesn't have a dominant quality and the tune will never have a tension-release feel when back to i. The tension is created by the tritone interval between the third of the chord (F#) and the minor seventh (C). The F# should resolve to G and the C to Bb. D minor doesn't have that interval (there's a perfect fifth between F natural and C) so no tension and that's why no dominant quality there.

From this point of view, I can tell you that any dominant chord always has its ninth grade implied. So, for a D7 chord, you can add the ninth (major second plus an octave) and it will sound great. The chord is now called D9 (D-F#-A-C-E).

Now, if you're concerned about playing a walking bassline over a D9 chord, you should never play an E on the downbeat. On 98% of the times, the root of the chord should be played on the first beat of the measure when playing a walking bassline. The other 2% is for the third or the fifth of the chord. I don't want to say that you CAN'T play the E on the first beat since some folks may say that modern music allows so many things, but I'm sure that more than one listener will be like . It works fine on the other beats since it's an scale tone. Be aware that the "downbeats" shouldn't be understood from the rhythmic point of view alone, but also harmonically. If you have four different chords in a 4/4 measure (one per beat) every beat is a strong one, so you must play strictly the roots or the alternate bass if indicated.

Of course, this is my sole point of view based on what I was taught. Maybe other fellow TBers have another opinion, but hope this helps.

3. ### bassjus

Mar 30, 2004
Mass
I completely agree with this man. Couldn't have explained it any better.

Apr 10, 2005
However, if I use the D7, which I understand a least a little why (thanks to your articulation), why do I use the F#, when it's not in the key?

Gmin => G, A, Bb, C, D, Eb, F, G.

I don't get it. I see where the D is the fifth degree of the key. 5th degree of the key is dominant (flat 7). I buy that. What I don't buy is the use of F# there. Man, I'm so close to seeing the light, I can taste it.

Thanks for everyone's responses. Theory is everything and challenging.

5. ### Alvaro Martín Gómez A.TalkBass' resident Bongo + cowbell player

Because you're limited to the natural (Aeolian) minor scale. This scale appeared as the relative minor of the major scale, which has as a prominent feature the seventh grade at a distance of a semitone from the root (A-Bb in this case). This creates the necessity of resolving. But the natural minor doesn't have this. The seventh grade is a whole tone apart from the root (F natural-G for this situation). That's why the harmonic minor scale appeared: Because that tension/release feel was needed. So the seventh grade was raised one semitone (from F natural to F sharp in this case) and that solved the problem.

But this created a new one: By raising the seventh grade, the distance between the sixth grade and the seventh became an augmented second (Eb-F# here), which was considered a "bad" interval for creating melodies, so the sixth grade was also raised (Eb to E natural for our example), creating a whole tone distance between the sixth and seventh grades. This was called the melodic minor scale. Again, problem solved.

BUT... this created a new one: The major scale is divided into two tetrachords (two groups of four sounds) which have the same intervallic relationship: whole step-whole step-half step. The second tetrachord of the melodic minor scale has the same relationship and it has a "major" flavor, so for compensating this, the alterations are removed when descending. Some call this the mixed melodic minor scale.

Summarizing:

Bb Major: Bb - C - D - Eb - F - G - A - Bb

G natural (aeolian) minor scale -minor relative of Bb major: G - A - Bb - C - D - Eb - F - G

G harmonic minor scale: G - A - Bb - C - D - Eb - F# - G

G melodic minor scale: G - A - Bb - C - D - E natural - F# - G - F natural - Eb - D - C - Bb - A - G

Hope this helps.

Apr 10, 2005
I will need some time to digest what you wrote but I follow most of it.

Actually what you wrote brings up more questions for me to answer, which is a good thing actually.

I can't express enough how much I appreciate you passing on your knowledge.

Thanks again.

7. ### Alvaro Martín Gómez A.TalkBass' resident Bongo + cowbell player

My pleasure. I'm really happy to help if I can.

8. ### Skeletomania

Oct 25, 2005
hong kong
I myself started learning blues with an instructor and this post is very intriguing. I do not have a single clue what you just typed, but I know you're using dominant 7 fingering position which gives the f#. Are all blues uses dominant scale and how does it apply to the blue scale(G-Bb-C-C#-D-F-G)

9. ### Ed Fuqua

Dec 13, 1999
Columbia SC
Chuck Sher publishes my book, WALKING BASSICS:The Fundamentals of Jazz Bass Playing.