What's the right name for this chord?

[ashcatlt]

It's spelled B-D-F-A.

I've been calling it Bdim7, but I think that's wrong. The dim7 is double flatted, no? Should be Ab, but it's in the key of Am, so that can't work.

Any ideas?

[JohnH]

entering it into this site:

Chord Finder

suggests that it is a Dm6

I wouldn't know if that is true though

John

[lpf3]

These guys are calling it a Bm7dim5

www.cyberfret.com/scales/guitar-codex/index.php#

1, b3, b5, b7 .....

The reverse chord is like John said - Dm6.
(What's a reverse chord?)

FWIW I've always thought of chords in that shape as diminished chords.

-lpf3

[4real]

hey there

this is a half diminished chord...B half diminished

this chord may be unusual but is in fact diatonic to the key of C major, that is it is the vii chord natural to that key. So for instance the vi7-vii7-I7 in C major would be Am7-B1/2dom-Cmaj7 as in below...

----------------------------------------------------------
-----1---3---5---------------------------------------------
-----0---2---4-----------------------------------------------
-----2---3---5---------------------------------------------
-----0---2---3-----------------------------------------------
----------------------------------------------------------

see how all these notes and harmony are all from the C major scale.

As Aminor is the relative minor to C major, it can be used in this context to as part of the natural minor, however it is rare in any context. In minor modes, these things can vary a lot with things like the melodic and harmonic minor and various minor modes being very common (aeolian and Dorian for instance are very typical).

The full diminished chord is far more commonly found but except in some minor modalities, is not natural to that key but a chromatic harmony...say B,F,Ab,D...that is a full diminished chord (as it is symmetrical (all intervals are minor thirds) any note may be the root. It is a kind of common chromatic harmony.

Full diminished chords are often found in jazz and other musics as a pivot chord useful for modulations or dissolving a sense of tonality or as a kind of dominant 7th function or as a kind of leading tone into diatonic harmony, all kinds of uses.

The half diminished, in fact the vii chord in general is not used nor it's mode (locrian) as it contains a big tritone (notes f to b) that can sound harsh. Therefore, it is really only necessary to know that these things exist I suppose and not worry too much about it.

In minor modes, it is not uncommon for say in Aminor for the ii chord to also be a minor7 such as Am-Bm (think of the vamp to "moondance") and associated with the dorian mode or the melodic minor modes which include F# (commonly the IV chord will be major in this minor key).

In harmonic minor and or more typically aeolian or natural minor, the iv chord would be a minor (dm in the key of Am) and so the note F would be natural...in such tunes, the ii chord would be say Bm7b5 (B,D,F,A) and so is effectively the chord you mentioned (a half diminished) by a more commonly found and appropriate name.

D minor 6th is spelled with the same notes if the root is D I guess (D,F,A,B) but not a very common sound or chord. This is one of the failings of chord finders and programs, it can't take context too much into account and as half dim chords are so rare, they default to the more common thing...it senses the minor triad (d,f,a) and adds the b note which is the sixth, I suspect.

anyway, i know this stuff can be confusing, but you are on the right track, the dim chord should have an Ab in it, being full diminished. The best name is probably the jazz convention of Bm7b5 I think. hope that helps...pete

[sumgai]

Pete gets it right, it's a Bm7♭5.

It can also be called a Dm6, but in this case, the 6th note is below the triad, so it should be nomenclated as Dm/B, spoken as "D minor over B".

I won't get into it any more than Pete has already done (and excellently so, +1 to ya, Pete!), except to add that a diminished chord denotes at least two notes flatted from the original. (Contrast this with 'augmented' versus 'suspended'.) Thus, calling something "half diminished" is not really correct, it's actually a flatted note, shown as "♭5" or whatever.

HTH




sumgai

p.s. You can get the "official" flat note representation by typing ♭ instead of a lower-case B.

[sydsbluesky]

*woosh*------->

[sumgai]

OK, syd, we'll start over, from the top. Where'd we first lose ya?

[ashcatlt]

Bm7♭5, then. This seems like a long way of saying it, but I guess I'll go with it.

Somehow, I'm not buying it as Dm6. Partly because it is firmly rooted on the B, the bass plays "fifths" between the B and F, and...well...I want it to be diminished! On the other hand, though, if you was to take the D natural minor scale and build a chord including the 6th (I-III-V-VI), you'd end up with D F A B♭. I call that Dm6, but that's not what the chord finder linked above is telling me. So then what is this chord that starts on D and actually includes the minor 3rd and minor 6th?*

The original question actually came up because I was learning "This Wheel's on Fire" which has a Bdim7 in it. I had been playing it basically the same as the "Bdim7" in my song, but realized this was wrong. Can anybody confirm or deny that the chord in "...Wheel..." should be spelled B-D-F-A♭?



*B♭M7

[gitpiddler]

Nice post pete!

lpf3-inverse (reverse) chords are the same notes stacked different,
or in a different key...

syd-see special characters thread ;D

[ashcatlt]

See now, I always thought half diminished was a major third and diminished fifth. Like B♭-D-E. I play with these things all the time, what with my penchant for whole tone scales. What are they actually called?

Wiki says that the chord I originally mentioned is a "half-diminished-seventh" chord. Another page I just read seems to consider all diminished chords to include the double-flatted seventh (sometimes known as the major sixth), and calls the one where the seventh is only flatted once "half-diminished".

Now I'm really confused. I don't intend to change what I'm playing, since it's the right chord for what I'm doing. Just wondering what to call it in the tab.

In the song where it matters, it's taking the place of the (sort of) related dominant chord until the last verse, where it finally gets down to the big clanging Em. Lends a certain sense of malaise through most of the song which is finally released in a satisfying sort of fury.

[sydsbluesky]

Yeah.. special characters don't seem to go so well for me on my laptop, unfortunately.

Pretty early, actually, Sumgai. This was never my thing. I tried to take music theory in high school, but it was independent study along side the guitar class and the teacher only gave us about two weeks worth of work all year... somehow still has his job...

I should add that I got an A on our one and only test. One of the most satisfying grades of my life. Took two hours.

I'll just try to stand back when Ash releases his malaise and maybe pick up some reading in my spare time... (music for dummies.)


I promise that this area of my life will be revisited soon... I'll be more than happy to pick everyones' brains when it does. ;D

[sumgai]

syd,

Understandable.

There are lots of websites that present various aspects of music theory, but just as ash is finding out, some of them are better than others. (I'm referring of course to the fact that they don't all agree on what to call a chord.) Instead of linking a few for you, I think it's better to let you set your own pace and decide when to jump in. At that time, I'll recommend only generically that you pay attention to jazz-oriented stuff. They're they ones that get into multi-part harmony, also better known as chords. (Or as some would call them, moving chords.)

While the classical crowd (aka the "long hairs") was first on the scene, they've been all but completely displaced as authorities on how to name chords. Even if you're not into jazz at all, these are the people who know schiesse from Shinola when it come to music - you won't go wrong by listening to what they have to say, both teaching-wise and musically.

HTH



sumgai

[sydsbluesky]

I'll keep it in mind.

Thanks, Sumgai.