The Important DIFFERENCE Between m7b5 And Half-Diminished 7 Chords 

I travelled from Manchester to meet a friend in London. He travelled from Paris to a destination he insisted on calling Londres. “That’s OK”, I said. “Two different names for the same city.” He shook his head sadly. “No. We started in different places and will return to different places. Therefore we are not now in the same city” In the confusion thus created he left and I picked up the tab.

I think the most important question here would be whether people actually use these terms this way. Because I have never heard of anyone making this distinction, and I haven't seen people using the m7b5 and half-diminished symbols in different ways - often people choose one or the other and use it for all chords of the same type, a bit like people either choose "maj7" or the triangle symbol. In the end, both "half-diminished" and "m7b5" are just two easier ways of referring to the chord that is actually called "diminished-minor 7th", similarly as full-diminished would be "diminished-diminished 7th" and dominant 7th would be "major-minor 7th". These are simply terms that people have come up with to make the 7th chord naming a bit simpler. It's easier to say (and distinguish between) "dominant", "major 7th" and "minor 7th" than "major-minor 7th", "major-major 7th" and "minor-minor 7th". My point here is that these are just "spoken language" terms that have become somewhat standardized. They aren't really formal terms. I know that a counter argument to my post could be that "but those people are using the terms incorrectly", but I disagree - these labels aren't "formal" and they aren't 100% standardized either. We are basically talking about the "spoken language" of musicians. Both of these chords - the vii in major key and the ii in minor key - are derived from the same degrees of the diatonic scale. These are the scale degrees 7 2 4 6 of the major scale and the scale degrees 2 4 (b)6 1 of the minor scale (for example notes B D F A in C major and A minor). It is exactly the same chord and has the same origin. Also, the use of half-diminished chords predates dominant 9th chords - they can't be derived from dominant 9th chords, because half-diminished chords were used before dominant 9th chords were a thing. It's simply the diatonic VII chord in the major key. Similarly, the IIm7b5 isn't actually derived by lowering the 5th of a normal IIm7 chord. It's simply the diatonic II chord in the minor key. I think all of this stems from the common misunderstanding that "diminished" always means "substitute for dominant". That's not the only use for diminished chords. Classical musicians have been using the diminished triad as the ii chord in a minor key for ages (and in classical music, this is pretty much as common as using the diminished chord as the vii chord). And if you look at full-diminished chords, their only function isn't a "rootless substitute for 7b9" - you have common-tone diminished chords and chromatic passing diminished chords, and they are all full-diminished chords, even though they are functioning in completely different ways. Actually, if you look at classical music, the half-diminished chord is much more likely to be used as a ii chord than as a vii chord. Going vii half-diminished I is fairly rare. Going ii half-diminished V is done all the time. The ii chord is often simply inverted (1st inversion is most common, 2nd inversion is fairly common). The third inversion is used over tonic pedal points where you usually alternate between the i and ii chords over 1st scale degree in bass. Even in major keys, the most common use of the vii half diminished chord is to continue to the chord a fifth below. It's mostly used in sequences - IV vii iii vi ii V I (and yes, even in classical music all of these chords may be 7th chords, except maybe for the I in the end). The full sequence is rarer in major keys, though - it's much more common in minor keys. I do understand where the name of m7b5 comes from, though - jazz musicians probably started using the term because IIm7b5 V7 I and IIm7 V7 I are so similar. But just because the chord has two (or more) different uses doesn't mean we should name it in a different way based on that use. Chord symbols aren't functional symbols. They simply tell you what notes to play. We don't do this with any other chord. We don't use a different symbol for tritone subs or backdoor dominants, or non-functional dominants, even though those chords are used way differently than regular dominant 7th chords (and we need to remember that the term "dominant" comes from the fact that it's built on the dominant - the 5th degree of the scale). And similarly, diminished 7th chords that have different functions don't have different names either. If we don't do it with any other chord, why should we do it with half-diminished chords? Actually, jazz chord symbols often have incorrect enharmonics any way (which BTW I don't have a problem with - often these "incorrect enharmonics" are used to make the chord symbols easier to read), so I really don't see why there would need to be a distinction between the same chord that functions in a different way. Functional analysis is better done with roman numerals than chord symbols. Chord symbols are simply a shorthand that makes communicating collections of notes much faster than having to write all of the notes out on sheet music.

This all fell into place when you showed how the resolutions worked in jazz as opposed to classical. Good thinking.

I love how he always talks like he was just beginner so he can interact with most of us, while it's actually a deep talk.

It's a bit like some words are spelled exactly the same but have completly different meaning and are used in completly different contexts and someone says "But it's the same word!"... no it's not.

Thank you for providing a very good explanation of context. The voice leading is important if you have a tonal center. Your mastery of harmony continues to amaze me! Thanks for putting up all these useful videos!

Finally learning this -- wonderful explanation. I'm having more trouble getting to the min7(b5) than resolving from it, particularly coming from the IV when I'm substituting min7(b5) for the ii. Thanks for the great education!

I am just learning m7b5 shapes this week and came across this question myself. What a timely video! Thanks!

Wow. This was sooo eye-opening! Amazing lesson, again. 🙌🏼

This is eye opening! Thank you for sharing this knowledge!

my friend, I love your humour, your channel, and your ethic-minded approach to brilliant clear descriptive renderings of questions ive always wane answers to and even ones i didn't know I didn't understand..... keep going brother loooooove your channel!!!!

Excellent, thank you! Context & intent are everything and this proves it.

I get your point but both names are used interchanged all the time... If you look at Berklee books they teach the seventh grade of the major scale as a -7b5 and this one resolves up by a semitone, I don't think those guys are wrong, it's just two ways of calling the same thing, I think the title of this vídeo could have been "The two functions and names of the same chord"... In fact I believe that actually speaking the name -7b5 is nonsense because if a minor chord has a flat 5 then it's no longer a minor chord, since a minor chord is Root, b3, P5, if You don't have a perfect fifth then it's no longer a minor chord strictly speaking but it's just one of those things people Say to communicate and I believe that in the jazz context they came with that name as an easy way to explain someone how to play a half-diminished chord easily, like they said to a pianist "Play a minor 7 chord, now lower the 5th a semitone" and that was easier than saying "Play a half-diminished chord" or explaining to that person the intervalic structure of the chord 🤣🤣😅🤷🏻‍♂️🤭

Thanks so much for the perfect explanation! I was confused over decades, but now I got the enlightenment 👏👍😃

Well I didn't know that. Thank you for the instruction. Love your work mate. Cheers.

Thank you for this very good explanation. This reminds me of the dominant 7th and the German Augmented 6th chords.

What a great explanation! Thank you very much. Love your videos. Cheers.

As a classical musician i tend to treat them as different functions of the same half-diminished chord, because the first example C minor is the relative minor of the second example Eb major, and they share the chord of Dø7 (or Dm7b5)

Very interesting, well organized and presented.

Thanks for this clarity! Subscribed.

Great lesson! Thank you so much!

I’ve recently noticed that those chords are functioning differently but I couldn’t completely organise my thoughts about it. And now this video shows up just like a miracle. Thank you !

Jazz musicians refer to musical “vocabulary”, and just as you describe this chord, there are many spoken words spelled and pronounced the same but have completely different meanings which depend on their placement in a sentence and/or the other words nearby. But the word is spelled the same no matter how it is used. Likewise, same chord different “meaning”.

Great lesson. Thank you for sharing

Appreciate your honesty. And your style of teaching. And your accent. Rock on brudda ty

This is great! Thank you.

at first , i was surprised , then after watching the video , it makes sense... furthermore now it is clear to me where the name half-diminished comes from... thank you

This is all very fascinating!! However, at the end it is in the application! ! No wonder there is so much confusion between jazz and classical!! 2 different worlds but same results!! Thanks for sharing!! 👍 👍

Makes sense. Love your lessons

All of your 'Video's, are concise, and easily understood, even to non-musicians .Thank You

1. Classical music also usually uses diminished chords in first inversion in order to avoid the tritone they put above the bass in “root” position so VII° looks like it is supposed to be a substitution for IIm, which is another premise for resolving it by step. 2. So you can ostensibly resolve IIm7b5 down a minor third to avoid playing a major third above the bass in a minor key, e. g. Dm7b5 Bø~B°7 Cm? Or resolve bVII9 down a minor third to avoid playing a minor third above the bass in a major key, e. g. Bb9 G7 C?

So does m7b5 have subdominant function and half diminished 7th have dominant function?

This is really really cool. Thank you sir!!!

Thanks a lot! Very useful for a pianist as well

That's for this, I had no idea that there was a difference until now.

Right at the end when you explained the resolutions, I understood everything.

Simply a technicality, the half-diminished chord can have different functions according to the key we’re in. Just like any other chord. No need for 2 different names.

Awesome. Really useful to know this

True story man! Im a jazz player and clasical at the same time.

Man, this is just enlightening. I am an amateur pop songwriter, and in some songs I use the Bm7b5 G7 Cmaj7 progression. It always felt quite not right labelling that chord Bm7b5 since it clearly doesnt have the same feel as usual (say in Bm7b5 E7 Am). I can see it all so clearly now, it was a B half diminished all along !

Naming/labeling things is the heart of music theory. It helps us to recognize structures and communicate ideas more clearly. I have no problem giving a new name to any structure that functions in an independent way. Common practice music theory is full of renamed structures, including minor/major keys and triad inversions. The precedent is in place to name functions rather than to give only one name to a group of notes. So, if one disagrees with the concept of gregarious naming, they would be in opposition to the approach long since established in western music theory. Also, one of the best parts of being a music theorist is that we get to name things. This often happens years or decades after the music is originally written. Example...Scriabin did not label any Mystic Chords. Music historian A. Hull coined that term 6 years after "Prometheus: the Poem of Fire" debuted. Thank you for the thought provoking content.

Context is everything!!

you are great to me .....i hope you inspire me more..

you make theory fun dude, thanks for being an amazing teacher.

Great lecture!

Like the keys of CM and Am they are _enharmonic._ You can take any chord and move the root to any other note in that chord and rename it (the same with scales, this is how we get modes). An Am7 chord can become a CM6 chord, even though they are the same exact notes: Am7 is A, C, E, and G and CM6 is C, E, G, and A. The difference is CM6 is not used in the same way an Am7 is used. As Tommaso demonstrates, it depends on the context what the function of the chord is in a given situation.

I love your videos and always either learn something or have parts of my own knowledge reaffirmed. I view you as a master of the material that you present. So please understand I don't disagree with you on the theory or your presentation of it. However, sometimes in practical application, whether performing these chords in someone else's charts or writing with them in my own, I have had to learn to think of these chord names as synonyms to either play the correct chord pitches expected of me or to have others play the correct chord pitches I have written, even if the naming convention is incorrect. I long ago found this necessary because there are so many chord types and naming conventions, along with multiple ways to write symbols for those chords that my brain just needed simplification to be able to ”grab” the correct group of pitches at the right time during performance. That was the only way I was able to carry out my job playing guitar on big band jazz charts, with the thousands of chord and voicing choices. My brain just seems to remember certain types of naming convention over others. Even if, theoretically, the naming I sometimes use is incorrect, my ears are just as happy to hear the correct pitches. Thanks for your knowledge and hard work!

Ciao Tommaso! I think we can see the main difference between these two chords when we expand them. While the m7b5 should maintain regular intervals as second grade of the major scale(except for the 5th, which of course we altered), the half-diminished should maintain the classic "locrian-sounding" intervals. Therefore I would expect the m7b5 to have a major 2 as an expansion, while I think the half-diminished should have a minor 2, following the intervals of a locrian scale. (I took the 2nd as an example, but it's also the case with the 4th and 6th) m7b5: R-2-b3-4-b5-6-b7 h.dim.:R-b2-b3-b4-b5-b6-b7 Did I explain myself well?🤣

I'm not sure I will ever get to a level of playing where I will actually use any of this stuff but I love watching your videos for the sheer beauty of the theory. Great work, man. Thank you so much.

Interesting but the "two" chords are still related diatonically. VII degree (acting as a dominant) in a major key, and than becomes II of the relative minor. Furthermore, there're a lot of examples in classical music where the chord is used as a second degree in a minor key (Mozart's Symphony n°40 or Bach's prelude n°10 from The well tempered clavier). So your distinction between its use in jazz and in classical music at the end doesn't seem accurate to me.

Thanks for explaining, this has been confusing me for a while.

I see the the half-diminished seventh chord as having what I call "Dominant Seventh Below" function. For example, in the key of C minor the Fm chord (iv) is the dominant below (subdominant), and being minor, is built from the top down as C-Ab-F. Fm's seventh below is D, and this forms the chord C-Ab-F-D, the half-diminished seventh. This is contrasted with the "Dominant Seventh Above", which would be plain old G7 (V7) in C minor. In any key iv and V are reciprocals about the determinant so the half-diminished seventh chord is the reciprocal, or so-called negative harmony, of the dominant seventh chord. The correct fundamental roots of 4 and 5 are also symmetrical about the generating tone. It's used this way in a lot of cases too, where it may be called the "Money Chord", so what I am talking it's not just a purely theoretical construct. I use the functions a lot in my own music. Thinking this way also opens the door for subdominant leaning major and minor tonality, think "Harmonic Major", rather than the historically dominant leaning modes of western classical music.

Great video! When I started learning music theory, I looked up on google for instructions on how harmonize the C scale, but the vii chord was always shown as a diminished chord instead of a half diminished. Do you know the reason why? And also when they add the 7th note, they name the chord not as half dim but as b57

Just when I thought I wouldn't run into anymore enharmonics, I get this bombshell If this even counts as an enharmonic

Thank you brother

Tomaz, u rock! Thnx brother ❤ u r one of the best.

Very much thank you for all the music theory video

Thx for bring this out. In my opinion, one should concern the voice leading not from the name of chord nor classical nor jazz, but it’s functional use in the key. A Dm7b5 can thus be used for modulation.

Nice video, thanks.

I came here a little skeptic but maaaan, this makes so much sense. In school some teachers used to say "Bb7 (or Bb9) with omited generator" and I always thought "Come on, just say m7b5", but now it makes sense. It was just to demonstrate where it came from without actually saying it. Don't know if that makes sense to anyone but it does to me :)

Its an arnold schoenberg. Story In his harmony book he make resolve si re fa la chord to mi minor chord

Thank you. I'm wondering, What did you base on the assumption that the half diminished chord derives from the Bb9 and that the diminished 7th chord derives from Bb7b9? Can you add a link to an article or something? Thanks!

Thank you for your channel, and thank you for the spanish version. It may be an automatic translation, but just in case, I think "semi diminuido" is better than "medio disminuido".

How does your chord class work? Do you send pre-recorded videos everymonth?

How or where can I learn classical notation for inversions and bass?

Ironic I always recognized half diminished as rising by half step to tonic by means of dominant harmony, and recognized the m7b5 as a chromatic alteration of a minor chord that would resolve as an imperfect cadence in any harmonic resolution whether by 5th or other chordal movement, I never recommended my students to have a distinction. Yes it is enharmonic but only one exists naturally in a key center. Sensible and effective. Whether someone wants to argue about modal substitution or chromatic alteration, the fewer steps to identify harmonic movement and note choices the better, this really is a more clear path. Even if there are examples of a ii minor being altered in baroque harmony it is more common to be used as a half diminished modulation to a new key a half step above in classical harmony, and less likely to be a chromatic substitution in a more static chord movement in jazz standards. People will still argue and dislike the channel, but this should be easier to understand and recognize while reading notation or tab. So give the man his due!

New subscriber here, and i must say I love the channel! Now, isn't this the situation with the multiple possible names for altered chords in general, and isn't the best possible name the one that expresses the correct musical context of the chord?

Bravo!!!

I keep forgetting the explanation, and come back every year to watch this video again. I hope that's the last time. Lol.

Question. If your root is on the low E, what would be the “typical” or “most common” way to fret a m7b5 ?

Ok, the difference is the context. Great stuff! Appreciate it

Good morning, brotha!!!

It also makes a great substitution chord for a F minor: C, F, F-, C can become C, F, D-7b5, C. Here again the D-7b5, in really, is a G7b9 (the Dom 7th in the key of C)

Context is key. With the guitar being a "shape-based" instrument, it is easy to simply associate a chord shape with its common name and just run with it. I experienced this a couple years ago when I had to play a particular voicing of an add 2 chord where the 2nd was in the bass. At first I thought ot was just a dominant 9th sus 4; but given the particular context, that shape did not function as a suspended dominant chord.

Monk was thinking about this chord as a Fm6 as all the swing era before him. Jazz started to call it D half-diminished under the influence of be-bop guys studying classical music.

Just curious if this distinction would make any difference if playing with just rather than equal tempered intonation.

2:30 can anyone explain (or better, link a video) to why the altered minor chord functions like a II chord?

Never thought about that so a cool perspective and it probably checks out. There wasn't much specific mention in my uni degree between the classical department which taught us theory, sightsinging and SATB voice leading rules etc and the contemporary Dept that taught jazz amongst other things about this nomenclature. I do remember being taught by the classical Dept iiø as a nat and harm minor not iim7b5, for what it's worth. Music (like all) language is an evolving index to aural ideas and the language may have been modernised so I'm not suggesting they were or weren't correct, just saying that's how we were taught in uni. Just offering a take on the discussion and probably won't read any replies - I'm lazy like that. This reminds me of the argument of IV7b5 from the Lydian dominant (Mel min). The argument that is should be spelt as a #4 not a b5 which implies the Alt scale VII7b5 from Mel min. If the alt scale degrees 1 b2 b3 b4 b5 b6 b7 why do we call the chord built from it a VII7#5 or 7#9 should be VII7(b3) and the like..? I'm not actually disagreeing with half diminished implying the harmonic function of viiø to I resolution. But I think of the in my playing m7b5 is the quality of the chord spelt out in chord symbols and half dim implies the harmonic function. So combining the ideas, a m7b5 is just the spelling of the chord and context can be derived from the surrounding chords/cadence and ø implies the m7b5 has the specific vii - I harmonic function. So m7b5 might or might not be a ø depending on context and can be used all the time with or without harmonic implications as it is just a chord spelling but ø is a m7b5 spelling with a specific harmonic function implied. It explains why a lot of my teachers in jazz prefered the m7b5 spelling to ø because it is more ambiguous.. maybe.

Nice. And it confirms what I always thought: in the end we all depend on the guy at the Bass, Mate...

Good information, thanks. Although I personally I do prefer the Barry Harris/ Pat Martino perspectives that the Dominant chords come from the Diminished chord and not the other way around.

Nice! But I wonder... How many markers and whipers do you go through anually?

You could say that the words minute and minute are the same because they have the same letters, but one means 60 seconds and the other means very small. It's all in the context of the sentence in which they are used for the meaning to come out.

This is great.

You say that dm7b5 differs from dhalf-diminished seventh. I am unconvinced. What do you think of another designation of the same 4 notes, fm6? Does that also differ from the other two chords, even though it's spelled the same?

Hi, I know your course is not a book but do you have a book that has the type of information you give in your videos? I really like your presentation and content. I'm a bass player/composer and use a six string bass. Thanks

Wow, I just sat there for 9 minutes and realised that I understand the physics behind the SpaceX launch yesterday better than music theory! I need to study. I’ve got a lesson this week with my guitar tutor, he’s a jazz and classical player. I’ll mention this and pretend like I know what I’m talking about. He’ll probably start waffling on about ‘augmented eleventy thirds, with a minor twist and a three times diminished in the bass’ 😂 (I did enjoy the video though)

Ok so if I got this right, then the Ab tone in the half-diminished D chord is diatonic to the scale (of, e.g., Eb major in your example), whereas the Ab tone in the Dm7/b5 chord is not (as in your example we would be in C major). Correct?

What is the difference between Bm7/b5 and Dm6 in the 4th inversion?

I think nomenclature can be important to clarify certain distinctions. That's why we have double sharps or flats in certain contexts. I still don't agree with calling a Dm7b5 on a Cm context because the Ab is a diatonic degree, so it's a diminished chord on its nature and not a b5. If it appears on a C context it's obviously a m7b5 chord. By the way, does anyone know what the half refers to on a half-diminished chord? If anything we could call it diminished minor 7. And a °7 would be a diminished major 6 by enharmony (or a diminished diminished 7, if wanted to be more accurate).

So once again it all comes down to function like most of music theory and how to classify chords

Great video! I really appreciate your more in-depth explanation of issues like these. At 5:14 you said “B7 with a b9”. I think you meant Bb7 with a b9. Could the small circle symbol, (o), used to designate diminished, also possibly originate from being a figured bass number, with (o) referring to the root and therefore (o) with the line crossed through it meaning no root?

Can a m7b5 resolve up a half step? For that matter, do we name any other chords based on the direction they resolve? I've barely touched diminished chords so I admit my knowledge is a bit lacking here.

Actually I tend to use the diminished chord in jazz a bit as tritone substitution, so a 251 that isn’t Dm7, G7 C but Dm7, Db0,C . I’ve seen that quite a bit in John Mehegans books from the 60s. It voice leads a bit easier.

D half-dim has same notes as Fm6. Could you comment on difference (if any) between them? Thx

So I'm confused. Harmonizing a major scale in diatonic 7th chords produces a m7b5 for chord vii. How does this fit with the ideas in your video? I've wondered about the use of the that vii chord for some time.

I've always thought of m7b5 as ii of the minor key and half diminished as the chord built on the seventh degree of major. It may have been worth noting that the half diminished is the 7th chord found in the major key.

I watched this about a year ago and it didn't really sink in. Watching it again it makes perfect sense now. I think that calling the distinction pedantic is missing the point. Thinking of it like this emphasizes the fact that the chord can function either as a ii chord, or as a rootless dominant 9, and each implies a different resolution. A very handy distinction imo.

Really interesting. So many times I have encountered people insisting that inversions of different chords with the same notes(but different root notes), are the same chord. Like the example given by @Aylbdr Madison in the comments about Cmaj6 and Amin7, they function differently, despite having the same notes. You have expanded that idea to show how chords with the same notes AND the same root note function differently. Keeping this in mind, how would you go about naming the chord with notes C Eb G#? While people do mention that it is simply an inversion of Ab major, and I agree that C Augmented Minor is wrong, as it implies a major third, I am not sold on it simply being called Ab Major. If I play it as a chromatic alteration to Cminor, when it is the I chord (Gm -> Cm -> Cm#5 -> Cm). I think it should have a name with C at the root right?

What if you just have the notes B D F A and no musical context? Is there a default way that is best to call this group of notes?