More Questions about the Chord Progressions

[jushin]

I'm an enthusiastic learner, so I have many questions, so I think I'll need to stack all my topics together to the next topic just to avoid messiness in this forum

1.

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If you look at B9(b5), the chord was expressed as B - Db - Eb - F - A.
First, I could see b5, and 9, but there is extra A, which is nowhere at all in this notation. So why is there extra A in here? So I was thinking about it, and I've concluded that A was there to make a tritone with Eb to make a passing chord. Is this interpretation correct?
Second, this chord doesn't sound 9th chord at all, it rather sounds like a somewhat diminished chord. So I've concluded that the chord has two tritones (B and F, Eb and A), so it sounds like a diminished chord. Is this correct?


2.

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In the forth line, The music goes with G minor scale, with chord Cm7, and F7sus4, and it suddenly progresses with these chords that aren't in the diatonic scale. What kind of scale does these chords (BbM7, AbM7, GbM7, Fm7, Ebm7, DbM7, C7sus4) in?



3.

Is it just me that the chord notation is really confusing and unintuitive? Here's what I'm talking about;
If it's C major 7th, it is C E G B.
if it's C minor 7th, it is C Eb G Bb
Why then is it C minor 7th instead of C minor 7b th? If it's Cm, then it is C Eb G, so if we say C minor 7th, that should be C Eb G B. This doesn't make sense. Let's see another example.
If it's C Augmented Major 7th, it is C E G# B
If it's C Augmented 7th, it is C E G# Bb
So in this case, the former just used the 7th in the scale of C, but the latter didn't just the 7th, it actually used 7b th.
This collides with the fact that we note C minor 7th 5b as C Eb Gb Bb, which merely notes 5b as it is. Then why is other 7th chords doesn't get noted like this? It should be C major 7b th, not C major 7th.


4. If we look at B7#9, it is B - A,Eb,G,B. What's #9 stand for? It should be D, I guess, but it's not and there's G instead.

[sjm]

A 9th chord is expected to include the 7th as well as the 9. That's why there is an A (the 7th) in your B9 chord.

If you want the 9th without the 7th, you'd normally call it an add9, e.g. Badd9. This is then without the 7th.

The unqualified 7th is always a whole tone below the root of your chord. A7 contains a G; D7 contains a C; C7 contains a Bb.

The major 7th is a semitone below the root. AMaj7 contains a G#; DMaj7 contains a C#; CMaj7 contains a B.

The "major 7th" should not be confused with a major chord with a 7th:
C7 (C major chord with a 7th) = C E G Bb
CMaj7 (C major chord with a major 7th) = C E G B
CmMaj7 (C minor chord with a major 7th) = C Eb G B

That's also why it gets highly confusing when people feel the need to add "major" or similar to the chord names of major chords. Best to stick to no label for major chords to avoid confusion, otherwise you can't tell what Cmajor7 is or end up with nonsense like Cmajormajor7.

[jushin]

The "major 7th" should not be confused with a major chord with a 7th:
C7 (C major chord with a 7th) = C E G Bb
CMaj7 (C major chord with a major 7th) = C E G B
CmMaj7 (C minor chord with a major 7th) = C Eb G B

That's also why it gets highly confusing when people feel the need to add "major" or similar to the chord names of major chords. Best to stick to no label for major chords to avoid confusion, otherwise you can't tell what Cmajor7 is or end up with nonsense like Cmajormajor7.

Why is Bb a 7th of C7? In common sense, 7th should be B,in the same way that we call Gb a flat 5.

[ImNotDedYet]

Why is Bb a 7th of C7? In common sense, 7th should be B,in the same way that we call Gb a flat 5.

First, you have to remember there is C7, (or C Dominant 7th - a C Major triad w/ a minor 7th) CMaj7 (a C Major triad with a major 7th) and CMin7 (a C minor triad with a minor 7th)

The reason a C7 has a Bb instead of the diatonic B is because you have a minor 7th. So, if you take the scale of the musical key of the root note (scale of C Major in the case of a C7 chord) and find the minor 7th, it's a Bb and not a B. Same applies to all chords and their dominant or minor 7ths. G7 (G Dominant 7th) has an F natural because the scale of the key of G has an F#, so the minor 7th is F natural. etc. etc. etc.

[jancivil]

B9(b5) expressed as B - Db - Eb - F - A.
I've concluded that A was there to make a tritone with Eb to make a passing chord. Is this interpretation correct?
Second, this chord doesn't sound 9th chord at all, it rather sounds like a somewhat diminished chord. So I've concluded that the chord has two tritones (B and F, Eb and A), so it sounds like a diminished chord. Is this correct?

As indicated already, the symbol B9 conventionally is taken to include the 7th, and that convention is major triad/minor 7th type, known as dominant seventh.

So here we look at the convention in use, for popular type and jazz nomenclature and I'll indicate the expected intervals literally as I did above.

I do not hear tritones as per se diminished, no. I hear what it is, which as it happens is 5/6 of a whole tone scale. It's a thing, I know it immediately. Compare Stevie Wonder 'Sunshine of My Life'.

In the forth line, The music goes with G minor scale, with chord Cm7, and F7sus4, and it suddenly progresses with these chords that aren't in the diatonic scale. What kind of scale does these chords (BbM7, AbM7, GbM7, Fm7, Ebm7, DbM7, C7sus4) in?

What happens actually is ii-V in Bb to I, ii-V in C immediately followed by ii-V in D, back to ii-V in Bb. You know what I just noticed? The whole tone relationship of the blunt modulation of keys; now I see Bb Ab Gb; F Eb Db. Check it out. The landing is the C7sus and I expect resolution to F. So that's a kind of turnaround and as such a (compositional) goal.

Is it just me that the chord notation is really confusing and unintuitive? Here's what I'm talking about;
If it's C major 7th, it is C E G B.
if it's C minor 7th, it is C Eb G Bb
Why then is it C minor 7th instead of C minor 7b th? If it's Cm, then it is C Eb G, so if we say C minor 7th, that should be C Eb G B. This doesn't make sense. Let's see another example.
If it's C Augmented Major 7th, it is C E G# B
If it's C Augmented 7th, it is C E G# Bb
So in this case, the former just used the 7th in the scale of C, but the latter didn't just the 7th, it actually used 7b th.
This collides with the fact that we note C minor 7th 5b as C Eb Gb Bb, which merely notes 5b as it is. Then why is other 7th chords doesn't get noted like this? It should be C major 7b th, not C major 7th.

Where did you get '7th' means major 7th necessarily? Ok, here's the brass tacks of it, chord chart nomenclature cf. literal intervals. I'll show the quality of the 3rd and 7th divided by a slash:
Cm7 (C minor 7th) is taken as minor/minor 7;
C^7 (C major 7th) is taken as major/major 7;
C7 is taken as major/minor 7;
Cm^7 (C minor/major 7).

The next order of business naming these is the quality of the 5th; I mean that 3rd and 7th are established first. So, 'Cm7 b5"; C7b5; C^7#5; C7#5 etc.
In more academia-based theory, to say '_ seventh' is not definitive in itself: The I and IV harmonies in major happen to have major 7ths, ii, iii, V, vi & vii happen to have minor 7ths by default/in key. (Typically we're in the context diatonic/in key/triadic construction on Roman Numbers and there's no particular need to explicate the obvious.) In minor key we typically see how the conventional dominant V7 uses the 'leading tone' raised 7th per the key and we now can see our way to a diminished seventh, "#vii7" (minor/diminished/diminished). The m7b5 type, example ii7 in minor is known as 'half-diminished' (minor/diminished/minor).