7b in major chord

[cactus waltz]

Recently in my playing I have begun to naturally gravitate towards using a 7b in my major chords, especially for the tonic. I suppose I like the sound of it and it also carries less tension than a regular 7. I do wonder what it means theory wise:

1. Would it be considered a mixolydian scale, even if it's played over the tonic and not the fifth?

2. Are there any rules of thumb for when flattening or sharpening a 7th would make sense, musically speaking?

[slybass3000]

Originally Posted by cactus waltz

Recently in my playing I have begun to naturally gravitate towards using a 7b in my major chords, especially for the tonic. I suppose I like the sound of it and it also carries less tension than a regular 7. I do wonder what it means theory wise:

1. Would it be considered a mixolydian scale, even if it's played over the tonic and not the fifth?

2. Are there any rules of thumb for when flattening or sharpening a 7th would make sense, musically speaking?

It depends on the chord function in an harmonic context. In Blues harmony, the tonic has the sound of dominant (b7) on the I chord which is typical to the Blues harmony.

But, if you like the sound of it on a first chord for example, it means in general that you like the sound of the Blues which is present not only in Blues but in Jazz, Rock, Pop, Funk, R&B to name a few styles that are based on this sound.

As long as the Major 7 is not present or important in the melody, then there is no problem. But the b7 is an easy way out to bring movement in a bassline and shouldn't be overused on all major chords and the use of the 6 is better on major chords that function as a I or a IV in diatonic harmony when you want melodic movement.

[MalcolmAmos]

Originally Posted by cactus waltz

......2. Are there any rules of thumb for when flattening or sharpening a 7th would make sense, musically speaking?

Except for the blues which Sly covered the b7 added to a dominant 5 chord adds tension to that chord, thus the V7 wants to resolve RIGHT NOW. I can not think of a reason to add a b7 to the other major chords, i.e. the I or IV, except for the blues.

The b7 added to a minor chord gives you a minor seventh - not a dominant minor seventh. I think of this adding flavor and/or color instead of adding tension.

The 7 or major seventh Cmaj7 adds flavor and/or color but not tension as a b7 would.

My rule of thumb is the b7 can be added to the dominant fifth chord making it into a dominant seventh chords or on minor chords making them Dm7, Em7, etc. It is of course found in the Bm7b5 1/2 diminished chord. A full diminished chord has a bb7.

I may have missed something, but, I think that pretty well covers how the b7 is used with Major and natural minor scale/chords. Melodic and harmonic have their own set of rules. [edit] Well there is one more thing that can happen with a minor chord -- DmMaj7 for example, but, that is minor.

If you have not stacked 3rds yet might play with this. The maj7, b7 dominant, minor and diminished fall into place automatically when you stack 3rds. How do you stack 3rds. Take the scale and use every other note to form the chord.
C Scale = C, D, E, F, G, A, B
The C chord taken out to the seventh degree would be C, E, G, B. Compare this to the notes in the C scale and you get a chord spelling of 1-3-5-7 or the Cmaj7 chord.
The D chord (in C's scale) taken out to the seventh degree would be D-F-A-C. Comparing this to the notes in the D scale and you get a chord spelling of 1-b3-5-b7 or the Dm7 chord. Amazing! The D chord in C's scale/key should be a minor chord and it is. Look also how the seventh fits into the picture.
Take the rest of them out - that fish thing. I think this will throw some light on how sevenths are made and then used.

Good luck.

[cactus waltz]

Thank you for the replies,


if I've understood correctly, the 7b has worked as a blue note and not as a mixolydian scale, because of the function of the chord in the song. Very good to know. I'll likely experiement with more blues scale notes in major chords and see how it turns out.

[brammerd]

A major bebop scale has a b7 and a major 7.

You're not the only one that likes this

[slybass3000]

Originally Posted by brammerd

A major bebop scale has a b7 and a major

True, but it is not called a major be-bop scale, it is called either the bebop scale or mixo passing tone. The major bebop scale is the major scale with a passing note between the 5 and the 6.

But don't forget that the M7 in this case functions as a passing note and not a chord tone and so is the #5 or b6 in the major scale ;-)

[slybass3000]

Originally Posted by cactus waltz

Thank you for the replies,


if I've understood correctly, the 7b has worked as a blue note and not as a mixolydian scale, because of the function of the chord in the song. Very good to know. I'll likely experiement with more blues scale notes in major chords and see how it turns out.

Yes it does.

For me here are in order the color of the blue notes from light to dark: b7, b3 and b5.

Plus, I suggest you to experiment with the Major Blues scale which is in C : C, D, D# or Eb,G,A. It is the major pentatonic with a b3 or #2 in it.

[mambo4]

Originally Posted by cactus waltz

1. Would it be considered a mixolydian scale, even if it's played over the tonic and not the fifth?

2. Are there any rules of thumb for when flattening or sharpening a 7th would make sense, musically speaking?

1.) maybe.... But realize in blues and all its derived music(rock, soul, funk, etc etc) the idea of a b7 under the "tonic" is common.
It's not strictly diatonic harmony: in blues you play I7-IV7-V7, not Imaj7-IVmaj7- V7: the I is a dominant chord even tho it's the "tonic"...
In practice, early rock n rollers (Beatles for example) would emulate the rockin bluesy sound in a pop chord progression
Playing essentially diatonic progressions root-wise, but using Dominant chords all over the place - for the iii, the vi, the IV etc...

2.) the only real rule would be : avoid it if it sounds bad... basically if someone else plays the natural 7...