m7b5 or Diminished?

[bobsguitars09]

m7b5 or Diminished? what is the difference?

[bako]

They differ by one note a half step away.
Cdim---------C Eb Gb Bbb--------1 b3 b5 bb7
Cm7b5-------C Eb Gb Bb---------1 b3 b5 b7

Diminished could possibly refer to the triad but generally refers to the seventh chord.

[bobsguitars09]

Thanks. I was confusing a half dim with a dim.

Half Diminished is the same as a m7b5 right?

[bako]

Yes

Same notes arrived at from 2 different angles.

Cm7------C Eb G Bb becomes
Cm7b5---C Eb Gb Bb

Cdim------C Eb Gb Bbb becomes
Chalf dim-C Eb Gb Bb

[bobsguitars09]

when a chart says Cdim it means Cdim7 right?

[bako]

when a chart says Cdim it means Cdim7 right?

Most of the time yes.
Unfortunately the triad is indicated the same way.

[bobsguitars09]

Dim Triad is 1 b3 b5?

[JohnW400]

Not usually. In most charts I've seen you play dim7.

EXCEPT !!

The notable difference is in tunes like Corcovado where the melody is E natural against an F diminished. Here the voicing is more of a diminshed /ma7. You see this chord a lot. It's also an E/F ( F Ab Cb E which enharmonically is F G# B E). This chord is also in Triste by Jobim and Letter to Evan by Bill evans.


I'm sure there are tons of other examples, I just can't recall them righ tnow

[Luan]

That major 7th in the dim7 chord is just a note from the scale I think, rather than a chord tone.

[randalljazz]

at least several authors consider the diminished major 7th to be a chord in its own right. it functions somewhat differently than plain dim 7th. sometimes written as a slash chord:

B/C for a C dim maj 7.

[JohnW400]

Originally Posted by Luan

That major 7th in the dim7 chord is just a note from the scale I think, rather than a chord tone.

It's a dimished triad with a major seventh interval. I never called it that until I was nosing around the AAJ site and saw it it named that way by several musicians there. It made perfect sense to me and reaffirmed that you can learn something new everyday.

[Luan]

actually you can use tensions for dim7 chords, any tension that is a whole step over a chord tone, 9th, 11th, b13th, and major 7th.

[Luan]

Oh i see you guys refer to a triad without the diminished 7th interval, now I get it.

[JohnW400]

I'm pretty sure Bill Evans used it in Letter to Evan as an Eb dim/G (I think) so the voicing comes out as:

G Eb Gb Bbb D. Almost like a full polychord D over Eb. I'll check the score later to confirm. But it's a nice sound. Very Jobim sounding

I'm with you Luan, the 9,11 etc added to a full dim7 sound great.

[bobsguitars09]

Thank you!

[Jazzarian]

Originally Posted by bobsguitars09

Half Diminished is the same as a m7b5 right?

Yes indeed.

Perhaps you remember the locrian mode?