Proper use of m7b5 chords

[mambo4]

I recall reading -I can't remember where-
that many musicians don't know how to use half diminished (m7b5) chords properly. This was in a jazz context, i think.

The implication was that a m7b5 is NOT a viable substitute for a true diminished chord....but why not?

I know use is as the ii chords in a minor key ii-V-i progression...

and why do I care? i just play the root

[jzucker]

because a dminished chord has a maj7 and the half diminished has b7. If you only play the root, why care and why ask?

[ARCtrooper225]

Originally Posted by jzucker

because a dminished chord has a maj7 and the half diminished has b7. If you only play the root, why care and why ask?

no, diminished chords have a bb7 (enharmonic to a major 6)
A proper use would be wherever you think it sounds well

[Eli M.]

I hesitate to set forth "rules", but the "proper" use of a half-diminished chord would be to serve a predominant funtion like a ii chord (typically leading to the dominant).

[Correlli]

diminished chords have Dissonant charactertistics. In other words, they create tension and sound unresolved. Compare with Consonant.

[DocBop]

Common use of mi7-5 is as the II chord in a minor II-V-I. The common scale used is with mi7-b is Locrian #9.

[HaVIC5]

Originally Posted by DocBop

Common use of mi7-5 is as the II chord in a minor II-V-I. The common scale used is with mi7-b is Locrian #9.

Some people say that locrian #9 (I prefer the term Locrian natural 9) is the common chord scale associated with m7b5, but in practice, you really don't hear that natural 9 (the major third of the target tonic) all too often. When you use a m7b5 as a modal interchange chord in a MAJOR ii-V-I, its a lot more common. The natural 9 in the other context is a very special note that requires special attention, and shouldn't just blindly be used because its a "hipper" chordscale to use. In the vast majority of music, its straight locrian.

Minor 7 b5 chords CAN indeed function as diminished chords, although it is rare. If you define diminished chords as chromatic passing chords that connect two chords (they can function in an auxilary manner, but thats not as common), then the #IV-7b5 can and is used occasionally connecting V7 (or the I chord in second inversion) to a IV chord (sometimes a II-7). Some people actually insist that m7b5 chords shouldn't be called half-diminished in any other context BUT this one, since they feel that the term half-diminished describes chord FUNCTION (like dominant, subdominant, etc) rather than chord QUALITY.

[Audiophage]

It tends to lead to happier places.

[jzucker]

Originally Posted by HaVIC5

Some people say that locrian #9 (I prefer the term Locrian natural 9) is the common chord scale associated with m7b5, but in practice, you really don't hear that natural 9 (the major third of the target tonic) all too often. When you use a m7b5 as a modal interchange chord in a MAJOR ii-V-I, its a lot more common. The natural 9 in the other context is a very special note that requires special attention, and shouldn't just blindly be used because its a "hipper" chordscale to use. In the vast majority of music, its straight locrian.

Rather than call it locrian natural 9, why not define it as 6th mode of melodic minor? IMO, it's silly to define a chord/scale as an altered chord when it's part of the melodic or harmonic minor series. I agree that you can't just blindly use it but I use it all the time, even as the ii chord in minor keys where the natural 9 is the major 3rd of the minor key. I don't really think you can generalize though. The chord scales need to have the progression taken into account as well as the melodic line.

Minor 7 b5 chords CAN indeed function as diminished chords, although it is rare. If you define diminished chords as chromatic passing chords that connect two chords (they can function in an auxilary manner, but thats not as common), then the #IV-7b5 can and is used occasionally connecting V7 (or the I chord in second inversion) to a IV chord (sometimes a II-7).

That doesn't make it a diminished chord. If that were true, a any chord could be a diminished chord that chromatically connects two diatnoic chords. For example, in the key of G I quite frequently use a C#m7 4ths voicing (C# F# B E) to connect the IV and V chords or sometimes a B/C# (C# F# B D#)

The difference between the two is that the diminished chord is symetrical (stacked minor 3rds) and can be represented by the semetrical whole/half scale. The half diminished chord is really a min7b5 and it not semetrical.

[HaVIC5]

Rather than call it locrian natural 9, why not define it as 6th mode of melodic minor? IMO, it's silly to define a chord/scale as an altered chord when it's part of the melodic or harmonic minor series. I agree that you can't just blindly use it but I use it all the time, even as the ii chord in minor keys where the natural 9 is the major 3rd of the minor key. I don't really think you can generalize though. The chord scales need to have the progression taken into account as well as the melodic line.

Its not a mode, though, its a chord scale. Chord scales often resemble modes, but they are NOT the same. This is confusing, because very often they share the same notes (and names!), but they function in different ways. Modes are used to describe the same set of equivelant pitches with varying tonal centers to give certain musical impressions. The Greeks believed that each mode instilled a specific emotion in the listener, just by changing the tonal center among a group of pitches. When you're defining chord scales, you're looking at a far more vertical relationship, and you're not looking at the same group of pitches, you're looking at an ever fluctuating number of pitches based upon the chord structure of the moment.

What it boils down to is that when you're dealing with functional harmony, you ARE NOT changing tonal centers on every chord, which is why its called chord/scale correspondance, not chord/MODE. To describe it in terms of tonal modes rather than chord scales really isn't the correct analysis. Because, however, chord scales have the same NOTES as modes most of the time, they're called by they're modal name. For instance the II-7 takes the Dorian CHORD SCALE, not Dorian mode. It's confusing, yeah, but there is a very real theoretical distinction to be made. For chord scales like the locrian 9, the fact that its called "locrian" is utterly irrelevant as its status as the 6th mode of the melodic minor scale, its just a naming convention that people have adopted. It could just as easily be called the Aeolian b6 (and sometimes it is).

As to the question of the locrian natural 9 on a minor II-V-I, I do realize that some modern jazz educators and theorists advocate this, but it flies in the face of common melodic practice. I challenge you to find many, if any tunes with functional harmony that have that characteristic natural note in a minor II-V pattern, or any II-V-I pattern for that matter with a II-7b5. The only tune I can think of is Jobim's Angela, but thats the latter practice not the minor II-V one. If its a typical minor key tune, you should only take extreme care with the note, knowing that it is a very unique coloring that isn't very common in melody.

That doesn't make it a diminished chord. If that were true, a any chord could be a diminished chord that chromatically connects two diatnoic chords. For example, in the key of G I quite frequently use a C#m7 4ths voicing (C# F# B E) to connect the IV and V chords or sometimes a B/C# (C# F# B D#)

The difference between the two is that the diminished chord is symetrical (stacked minor 3rds) and can be represented by the semetrical whole/half scale. The half diminished chord is really a min7b5 and it not semetrical.

You're confusing here the concepts of chord FUNCTION and chord CONSTRUCTION. All diminished chords are built the same way and sound the same way (stacked minor thirds), but chords which aren't diminished chords can still have diminished function. Function is an important concept in tonal music, governing the way specific chords behave. Often a chord (like a V chord) is named based on its function (the dominant chord), but other chords can have dominant function in addition to the V (the bII7 with tritone sub, the VII in classical music, etc). You'll find that all diminished chords have similar function and behavior - they occur on a weak harmonic rhythm chromatically connecting two chords sepated by a major second. This is defined as diminished function. Diminished chords also serve a secondary function called auxilary diminished function where they resolve to a major chord on the same root (for example, Cdim, resolving to Cmaj7). These are the functions of a diminished chord in functional harmony, you won't find a diminished chord that doesn't do this.

We can extend that function to other chords that might serve the music in the same manner. The half diminished chord in the circumstance I provided can do that, and believe it or not, that chord that mentioned has diminished function too (although, to be honest, I've never heard of that being done, and sounds a little weird to my ears.) A much more common example of a minor chord being used as a diminished chord is in III-subV/II-II-V progressions where instead of a subV/II, you have a minor chord, so like in the key of G it would be B-7, Bb-7, A-7, D7, which are often the chords played in the turnarounds in How High the Moon. You have to analyze chords not only in their constuction, but their function within the progression as well.

[jzucker]

Originally Posted by HaVIC5

Its not a mode, though, its a chord scale.

Disagree. You're trying to mix classical and pop (jazz) metaphors. Not applicable here.

What it boils down to is that when you're dealing with functional harmony, you ARE NOT changing tonal centers on every chord, which is why its called chord/scale correspondance,

That's a new one. I've been teaching this stuff for 30 years and never heard the term correspondance, when talking about modes.

not chord/MODE. To describe it in terms of tonal modes rather than chord scales really isn't the correct analysis. Because, however, chord scales have the same NOTES as modes most of the time, they're called by they're modal name. For instance the II-7 takes the Dorian CHORD SCALE, not Dorian mode.

That's not a universal truth. That may be how you learned it but that's just an arbitrary system of what is "correct" and what is "incorrect". The fact is the sound comes first, then the theory. What you call it and attempts to limit what it's called are just silly.

[HaVIC5]

Disagree. You're trying to mix classical and pop (jazz) metaphors. Not applicable here.

Would you be so kind as to explain why my analysis is wrong and what your definition of "mode" is?

That's a new one. I've been teaching this stuff for 30 years and never heard the term correspondance, when talking about modes.

You're arguing petty semantics here. Chord/scale equivelancy, chord/scale relationship, chord/scale theory, whatever, its utterly irrelevant to the concepts it represents. Please address the broader points in my post, like the concepts of modal/tonal centers and what actually defines a mode versus a scale.

That's not a universal truth. That may be how you learned it but that's just an arbitrary system of what is "correct" and what is "incorrect". The fact is the sound comes first, then the theory. What you call it and attempts to limit what it's called are just silly.

Again, you're picking and choosing rather irrelevant points in my post to make argument with. Nowhere did I say that the II-7 only takes the Dorian chord scale, I merely said it takes it. I know full well that musicians and composers do other things with the II-7 chord than utilizing just a Dorian sonority, but the fact of the matter is, its not common. Music theory reflects general practice, and what we hear and what we see when we come across a II-7 chord in the vast majority of music (popular music). When we do hear something different, we have to put some other sort of analysis on it besides chord/scale theory, because the scale and sonorities being used don't have as direct a relationship to the chord as the dorian mode. For example, if you superimposed a locrian chord scale over a II-7, you couldn't really analyze it in terms of chord/scale equivelancy, because not all of the chord tones are the some (b5 on the locrican clashes with the 5 on the II-7). Nothing wrong with this, of course, if used in the proper situation, but you see you can't analyze it the same way you could in more typical situations.

Again, please go back and comment on the points about chord function versus construction and tonal versus modal analysis rather than attack points that weren't relevant.

[jzucker]

I'm not interested in dissecting your postings point for point. I just disagree with your rigid interpretation of the terminology. Jazz is a folk music. You can't force fit it into your terms.

[HaVIC5]

Originally Posted by jzucker

I'm not interested in dissecting your postings point for point. I just disagree with your rigid interpretation of the terminology. Jazz is a folk music. You can't force fit it into your terms.

Several things, I'm not dealing in rigid terminology, I'm talking in broader, abstract theoretical concepts. Second, what the hell have you been teaching for the past 30 years if, like you said, jazz is just a folk music and you can't analyze it?

[jzucker]

Originally Posted by HaVIC5

Several things, I'm not dealing in rigid terminology, I'm talking in broader, abstract theoretical concepts. Second, what the hell have you been teaching for the past 30 years if, like you said, jazz is just a folk music and you can't analyze it?

Are you deliberately being difficult? I didn't say you can't analyze it? I said you can't rigidly apply rules to it. The rules follow the music and not the other way around. If you want to know what I'm teaching about, feel free to check out www.sheetsofsound.net

[Skel]

I was just playing around with a Dm7b5. As long as I began with the II chord, being Dm7, it creates a natural walk down, resolving to the I chord (CM7)

[HaVIC5]

Originally Posted by jzucker

Are you deliberately being difficult? I didn't say you can't analyze it? I said you can't rigidly apply rules to it. The rules follow the music and not the other way around. If you want to know what I'm teaching about, feel free to check out www.sheetsofsound.net

I think the problem is you just have been misinterpeting my posts. I never meant to imply that music theory was a set of rules, it simply is a set of explanations based upon common practice and logic that can be interpeted in a variety of ways. I was challenging your explanation of how to think of going about tackling a m7b5 chord based upon the common definition of "mode" and what that implies, not based upon what notes SHOULD go with what. I've also argued what notes LIKELY go with what chords, but not what they will 100% all the time will take.

[jzucker]

Originally Posted by HaVIC5

I think the problem is you just have been misinterpeting my posts. I never meant to imply that music theory was a set of rules, it simply is a set of explanations based upon common practice and logic that can be interpeted in a variety of ways. I was challenging your explanation of how to think of going about tackling a m7b5 chord based upon the common definition of "mode" and what that implies, not based upon what notes SHOULD go with what. I've also argued what notes LIKELY go with what chords, but not what they will 100% all the time will take.

OK, sorry. We're probably just saying the same thing in different ways. Don't you love the internet.

[chicagodoubler]

OK

Let's actually talk about the OP's question.

m7b5 or half diminished is used predominantly in jazz harmony, as you can tell from the musings above.

Yes it is often used as a ii chord in a minor ii V, as in
dm7b5 G7b9 cm7

Try working through this progression on the tune Night and Day, by the fantastic Mr. Cole Porter. Here you'll find the chord in both its common manifestations- as a ii, and as a passing chromatic chord. Even more fun about working through this is that the tune uses the fully diminished as well, so you can really hear how the two chords differ.

Regarding scale choices- Locrian is the logical choice but regarding natural 2- I refer to the method Diz taught my friend and mentor Danilo Perez.

If you are just looking at chords and choosing predetermined scalar options, you might be completely ignoring the harmony implied by the MELODY! If the melody uses neither 2nd, you have (gasp) options. The third of the chord and the melody notes outline a "sound," and you can theoretically use any scale that fits this "sound," either as an inside or outside sound. The first rule is to learn all the rules. The second rule is to foget them all and explore music with a childlike sense of amazement...

[HaVIC5]

Originally Posted by chicagodoubler

OK

Let's actually talk about the OP's question.

m7b5 or half diminished is used predominantly in jazz harmony, as you can tell from the musings above.

Yes it is often used as a ii chord in a minor ii V, as in
dm7b5 G7b9 cm7

Try working through this progression on the tune Night and Day, by the fantastic Mr. Cole Porter. Here you'll find the chord in both its common manifestations- as a ii, and as a passing chromatic chord. Even more fun about working through this is that the tune uses the fully diminished as well, so you can really hear how the two chords differ.

Regarding scale choices- Locrian is the logical choice but regarding natural 2- I refer to the method Diz taught my friend and mentor Danilo Perez.

If you are just looking at chords and choosing predetermined scalar options, you might be completely ignoring the harmony implied by the MELODY! If the melody uses neither 2nd, you have (gasp) options. The third of the chord and the melody notes outline a "sound," and you can theoretically use any scale that fits this "sound," either as an inside or outside sound. The first rule is to learn all the rules. The second rule is to foget them all and explore music with a childlike sense of amazement...

Yeah, Night and Day has both manifestations of the m7b5, I forgot about that, that's a good example. Some people insist actually that the first chord is really an Abmaj7 rather than a D-7(b5), but really, both function the same way, so it doesn't matter all too much.

Good point about the melody, it should be the number one factor in note choice and then after than think in terms of the chord. Thinking more linearly, rather than on a chord by chord basis, can also help with note choice. For example, if there is no 2nd in the melody on the m7(b5), that note might appear in the next measure, giving you the option of contrast (using one 2nd in one measure and the other in the next) or continuity (keeping the second used in the next measure in the first. For example, if you're playing an A-7(b5)-D7(b9) progression and there is a Bb in the melody for the D7(b9), you can obfuscate the minor tonality a bit by emphasizing the B natural (creating tension) in the first and then returning back by emphasizing the B flat (creating release). Or, you can simply keep it within the tonality by having that B flat in both measures.

The point here is to conciously know what you're doing by playing what notes where rather than just thinking "OK, m7(b5), locrian, go!".