m7(b5)

Just a quick response to some of your question. I may be misunderstanding what you're asking and apologize if so.

The diminished chord ( m7b5) is part of the chord progression,

C Dm Em F G Am Bm7b5 C in the key of C for example. So, yes, it goes with any scale, I'd think. And it's always the seventh chord in the progression of the major scale.

Hope that helps somewhat.

Musenfeld has it right (except for a minor detail - it's a half diminished chord).

A full diminished seventh has three consecutive minor third intervals - as in C-Eb-Gb-Bbb - while a half diminished has a major third for the top interval, as in C-Eb-Gb-Bb.

Half diminisheds are what you get on the seventh degree when you harmonize four-note chords:

I = major seventh
ii = minor seventh
iii = minor seventh
IV = major seventh
V = dominant seventh
vi = minor seventh
vii = half diminished

You can create a chord progression that uses a half diminished without changing key, as in:

Bm7b5-Em7-Am7-Dm7-G7-Cmaj7

Tom,
Does that mean you'd name that chord a half-diminished B or would it be better to call it a Bminor7flatted fifth?
Tim

I'd go with the latter.

Tim, the preference seems to be changing. Years ago, it was just half diminished (the º sign with a slash through it), but then jazz started to make larger use of the chord starting in about the 1950s. If you look at some of the theory written in the 50s and 60s, there was a distinction made in the name based on how it resolved - if it went directly down a fifth in the root, it was a m7b5, and if it went anywhere else it was half diminished.

Common practice leans to m7b5 now in just about all cases. It's clean and concise. The only fault you could find with it is that it doesn't readily show the diminished triad as the root, but then if you're using this chord you probably already know that.

It's a pretty versatile chord, because of the symmetrical root... viewed with different notes as the root, it can be seen as other chord names:

Cm7b5 = C-Eb-Gb-Bb
Ebm6 = Eb-Gb-Bb-C (a perfect synonym)
Gb6b5 = Gb-Bb-Dbb-Eb

and it's closely related to some others with the addition of a single additional note:

Ab9 = Ab-C-Eb-Gb-Bb
D+7b9 = D-F#-A#-C-Eb (with F#=Gb, A#=Bb)

Personally, I think I'll just call it Fred. Until now, though, I'd never realized a chord could be half diminished.
Thanks!
Tim

I call it Barney. Fred's half diminished best friend! :lol:

Most chords I play are diminished in some fashion or other.

I lean towards the fifth. To drink that is :D so I would call it the Jack Daniels chord.

Tim and SirN, you gave me a great idea...

I was driving around running errands, and the Fred and Barney comments popped into my head. I think I'm gonna use that with young beginners to name the first two flats - the first one is Fred (key of F), the second one Barney (Bb)!

What would be the correct name for a chord as a vii triad?

1 b3 b5 for example is this just considered a diminshed 5th or something else.

Lee

thanks guys for clarifying things... I think I knew that a m75b chord can also be named a half diminished 7th from before, but it didn't click that if the 7th note of a major scale can have a half dim7, same way it can have m7b5, because they're the same chords! lol, should have got it... and thank you all again for being so friendly... :D

that means, I can use this progression as a ii-V-I --
Bbm7 - Eb7 - Abmaj7
Gm7(b5) - C7 - Fm7

in the key of Ab, am I right?

What would be the correct name for a chord as a vii triad?

1 b3 b5 for example is this just considered a diminshed 5th or something else.

LeeI think it's named diminished (eg. Bdim in C major scale)... then again... what do I know... :roll:

1-b3-b5 is just called a diminished chord (or diminished triad).

the progression you show would be a ii-V-i in Fm. Since Fm is built on the 6th note of the Ab major scale, the ii chord will be built on the 7th - G - which leads to a Gm7b5 in the natural minor scale.

Sounds great Noteboat. I'd say that's worthy of a free autographed theory book!

Or at least a discount?

Pleeeeeeease! :lol:

ok, just kidding.

Yaba daba dooooo :lol: