Theory & Impro C#7b13

[cappers]

Re the chord C#7b13.

I thought since C#maj7 is C# E# G# B#, C#7 is C# E# G# B and the '13th' is a flattened A# (13-7 = 6) it would be C# E# G# B A.

On checking on some chord sites I've seen C#7b13 written as:
C# E# B A
C# E# A B A
C# E# G# B D

Any suggestions appreciated.
Thank you.

 

[Ivan]

Inaccurate post deleted

 

[mrblackbat]

C#7b13 is:- C# E# G# B A; the A being the flattened 13th/6th. But you can also infer some other alterations, and this comes from understanding where the flat 13 comes from.

If we look at the minor scale a C#7 chord would be the dominant in, we can see where those alterations come from. C# is the fifth of an F# scale, and F# minor would be derived from the following scales:-

F# minor natural (Aeolian mode) - F#, G#, A, B, C#, D, E
F# minor melodic - F#, G#, A, B, C#, D#, E#
F# minor harmonic - F#, G#, A, B, C#, D, E#

You'll see that the A is the minor third of the scale, and so implicitly when you see a dominant 7 b13 then you can see that it's coming from the minor harmonic functions. In order to have the dominant "pull" towards the tonic, it needs to be a dominant chord - so the third has to be major and as such a semi tone beneath the root of the tonic - along with the 7th this is part of what creates the pull to the tonic, with the third moving up to the root. So that gives us C# - E# - G# - B - A. We can also easily add in the b9 from the harmonic minor scale - C# - E#- G# - B - D - A.

 

[cappers]

Thank you @mrblackbat

Glad I was correct about C# E# G# B A. I get the b9 D addition from the Hm scale.

Is the C# E# G# A B A correct? 1 3 5 b6 b7 b13. That was from a guitar chord site?!

The C#7b13 is in a solo on Autumn Leaves in F#minor. I was using the F#minor Harmonic over it.

 

[Pete Thomas]

Is the C# E# G# A B A correct? 1 3 5 b6 b7 b13. That was from a guitar chord site?!

It's fine if you want a crunchy sound with e A next to G#

C# E# B A
C# E# A B A

Yes, it's OK to leave out the 5th when voicing

C# E# G# B D

No, that isn't a C#7 b13, it's a C#7 b9

 

[cappers]

It's fine if you want a crunchy sound with e A next to G#

Yes, it's OK to leave out the 5th when voicing

No, that isn't a C#7 b13, it's a C#7 b9

Thanks.
I didn’t express that correctly.
I meant is C#E#G#BD a C# chord, which you answered as a C#7b9.
Ta.

 

[Pete Thomas]

Thanks.
I didn’t express that correctly.
I meant is C#E#G#BD a C# chord, which you answered as a C#7b9.
Ta.

I thought you meant you had seen C#b13 written as C# E# G# B D which would be wrong. It's a C# chord in that its root is C#. When we talk about a C# chord, what is usually meant is just the triad, ie just C# E# G# (and in many cases that is the tonic or IV chord rather than a V chord which usually has the 7 extension at least.

 

[Pete Thomas]

Is the C# E# G# A B A correct? 1 3 5 b6 b7 b13. That was from a guitar chord site?!

Further to my previous reply, that looks like an impossible chord to play without some radical (and IMO pointless) retuning of the strings. In terms of harmony (chord symbols) a b6 on a dom 7th would usually be referred to as b13, wherever it is voiced within the chord.

A b6 without the 7th would be extremely rare.

 

[mrblackbat]

It's fine if you want a crunchy sound with e A next to G#

Yes, it's OK to leave out the 5th when voicing

No, that isn't a C#7 b13, it's a C#7 b9

I guess the thing with the 7b9 chord and 7b13 is they are often largely interchangeable, as outlined above. (And #9 too)

 

[cappers]

I thought you meant you had seen C#b13 written as C# E# G# B D

This popped up on my browser when querying the C#7b13 chord:

​

C#7b13 is a dominant seventh chord with a flat thirteenth. It typically includes the notes C#, E#, G#, B, and D, where D is the flat thirteenth.

bb.steelguitarforum.com


For C#b13 I get this:

The C# b13 chord, also known as C# dominant 13th, typically includes the notes C#, E#, G#, B, D, and A. ​

scales-chords.com cochranemusic.com

Confusing! If C#7b13 is C# E# G# B A my Q is answered. Thanks.

 

[Pete Effamy]

Even more confusing is the fact that a FULL chord is talked about on a guitar site . Big chords like this sound a bit nasty on guitar and choices are made as to which notes get left out - which “colour “ notes suit the sequence better.

As Pete and Matt allude to, this would be common practice for pianists too in most situations, but on guitar some things are physically impossible, and where they might be possible - it could mean some rather nasty voicings.

 

[Pete Effamy]

Some parts of chords in functional harmony have such strong movement and identity that even root notes are not needed:

This is well-used and is basically a ii - v - I (in this case in the key of C):

A# B C
F# F E

The ii chord has been changed to a dominant type chord, say a D7#5;

Followed by a G7 and C as might be expected.

Play the notes on the piano, then after a few times add the roots.

 

[Pete Thomas]

C#7b13 is a dominant seventh chord with a flat thirteenth. It typically includes the notes C#, E#, G#, B, and D, where D is the flat thirteenth.

bb.steelguitarforum.com

I couldn't find that statement on the site linked to, however as you know D is wrong. I imagine it is a typo.

Confusing! If C#7b13 is C# E# G# B A my Q is answered. Thanks.

Yes, that's all you need to know.

Although (in the words of Columbo) just one more thing...

With extensions they often (but not always) mean to imply the inclusion of extensions lower down, but often with the exception of the 11th which is special case. So it is often OK to assume a 9th along with a 13th, but needn't be there unless actually specified.

Also beware of the contextxwhen reading stuff off the internet as chord symbols serve different purposes. Its one thing analysing a chord and another thing using a symbol as an instruction for a player when writing and arrangement.

 

[cappers]

Thanks one and all for your help.

The C#7b13 follows a Dmaj7 and precedes a G#m7b5 (half-dim) in the same penultimate bar, followed by F#m7.

I thought a B2 A2 / G#2 A2 C#1 / F#2 F#2 would end it simply. (Acknowledgements Bill Evans)

 

[wakyct]

Would it depend on what key you're in? In F# melodic/harmonic minor I think you'd have an Ab?

 

[PiccoloPirate]

Would it depend on what key you're in? In F# melodic/harmonic minor I think you'd have an Ab?

F♯, G♯, A, B, C♯, D, E♯, F♯

 

[wakyct]

F♯, G♯, A, B, C♯, D, E♯, F♯

Right, I was thinking b13 but I guess that's in relation to C# really so it's A?

 

[PiccoloPirate]

F♯ melodic minor

• Ascending: F♯, G♯, A, B, C♯, D♯, E♯
• Descending: F♯, E♮, D♮, C♯, B, A, G♯

F♯ harmonic minor

• Notes: F♯, G♯, A, B, C♯, D, E♯

AND, the F# minor scale would be?
Relative Major scale? 🏴‍☠️

 

[cappers]

Would it depend on what key you're in? In F# melodic/harmonic minor I think you'd have an Ab?

@PiccoloPirate beat me to it. The key is F#m and F#harmonic minor is A not Ab.

 

[Pete Thomas]

I’m completely confused now.