The Acoustic Guitar Forum

The Acoustic Guitar Forum (https://www.acousticguitarforum.com/forums/index.php)
-   PLAY and Write (https://www.acousticguitarforum.com/forums/forumdisplay.php?f=27)
-   -   Bmin7b5 (https://www.acousticguitarforum.com/forums/showthread.php?t=510253)

Guitars+gems 05-12-2018 04:12 PM

Bmin7b5
 
Someone gave me this chord, x2323x, and called it Bm7b5. Which fits my understanding of what a minor 7th chord would be, the major triad (the 3rd flatted and a flatted 7th added), plus here the 5th is flatted. So in this case, B D F A. Chordie is showing it this way, 124231, so with an F#. If you click on the chord to get alternative ways to play it, the F is used, not the F#. So, I guess it's just a mistake? But anyway, even if it was 123231, how would that be possible to play? Would you barre the first fret straight across and the second fret from the 5th string and then use the 3rd and 4th fingers for the F and the D on the 3rd fret?

Also, I think it sounds nice if the high E is played open, x2323O, So would that be Bmin7b5sus4? Ok, I know it doesn't really matter what the names of the chords are, but I like knowing.

Thanks

http://www.chordie.com/chords.php

rick-slo 05-12-2018 04:36 PM

One of my favorite chords to use is x23231. It is a moveable chord shape so the fingering is useful in various keys.
How?
Finger the 2323 frets the usual way. For 1 use the side of index finger.

Guitars+gems 05-12-2018 05:33 PM

Thank you for this, but what is the usual way? Because I've been using all my 4 fingers to play the 2323.

Also, Rick, I want to let you know that I took advice of yours ( to someone else) and have been playing the chords to Lay Lady Lay 10 to 20 times a day for the last 2 weeks. My ability to play Barre chords has improved so much that I'm actually excited about them and am using them in other songs and progressions. Thanks for that!

rick-slo 05-12-2018 06:36 PM

Quote:

Originally Posted by Guitars+gems (Post 5727025)
Thank you for this, but what is the usual way? Because I've been using all my 4 fingers to play the 2323.

Also, Rick, I want to let you know that I took advice of yours ( to someone else) and have been playing the chords to Lay Lady Lay 10 to 20 times a day for the last 2 weeks. My ability to play Barre chords has improved so much that I'm actually excited about them and am using them in other songs and progressions. Thanks for that!

Glad to hear it.
For the Bm7b5:
tip of index finger on 5th string
tip third finger on 4th
tip second finger on 3rd
tip of pinky finger on 2nd
index finger (just above middle joint) on 1st

Mark 63 05-12-2018 07:01 PM

This is also known as a half-diminished chord. It’s the 7th step chord in a major key.

Guitars+gems 05-12-2018 11:21 PM

Quote:

Originally Posted by rick-slo (Post 5727058)
Glad to hear it.
For the Bm7b5:
tip of index finger on 5th string
tip third finger on 4th
tip second finger on 3rd
tip of pinky finger on 2nd
index finger (just above middle joint) on 1st

Oh my! I read this thinking, "Oh yeah,right, I can do that." :rolleyes: In spite of my extreme skepticism I tried it. It took me a little to get the optimal hand position, so that the side of my first finger would hold the F cleanly, and the pinky finger wouldn't mute that string, but I got it! And it really is a pretty chord, and leads nicely to my next chord, E7. I'd have never thought to use a finger that way.

Thank you, Rick!

Guitars+gems 05-13-2018 12:23 AM

Quote:

Originally Posted by Mark 63 (Post 5727069)
This is also known as a half-diminished chord. It’s the 7th step chord in a major key.

My son, who gave me the chord, said that too. B1/2dim7 I think he said. So, I know that a diminshed chord is one made up of 2 minor thirds. And I think a diminished 7th chord has 3 minor thirds? This Bmb7 is made of 2 minor thirds and a major third. I don't get where the "half-diminished" term comes from. I mean, if 2 of the 3 intervals are minor, why is it only half diminished?

Ok, I'll look this up tomorrow. It's hurting my brain right now.:hmm:

JonPR 05-13-2018 05:22 AM

Quote:

Originally Posted by Guitars+gems (Post 5727219)
My son, who gave me the chord, said that too. B1/2dim7 I think he said. So, I know that a diminshed chord is one made up of 2 minor thirds. And I think a diminished 7th chord has 3 minor thirds? This Bmb7 is made of 2 minor thirds and a major third. I don't get where the "half-diminished" term comes from. I mean, if 2 of the 3 intervals are minor, why is it only half diminished?

Your "stacking 3rds" concept is what's confusing you. Chords are best understood as intervals measured from the root (3rd-5th-7th etc):

"Major" chord = chord with major (larger) 3rd
"Minor" chord = chord with minor (smaller) 3rd
Both chords have a "perfect 5th" (7 semitones from the root), so it's the 3rds that distinguish them, give them their character, and is where they get their names. The interval between 3rd and 5th is irrelevant.

"Diminished" chord = chord with a diminished 5th (6 semitones from the root).
"Augmented" chord = chord with an augmented 5th (8 semitones from the root).
Here it gets a little more complicated, admittedly. The dim triad has a minor 3rd and the aug triad has a major 3rd, but in both cases it's the 5th that's more distinctive than the 3rd, giving each chord its essential dissonant character.

When it comes to 7th chords, the shorthand names get a little less consistent, but still refer to intervals from the root. Intervals between other chord tones still play no part in chord names.

"Major 7th" chord = chord with a major (larger) 7th interval. You can have "minor major 7th" chords too, which have a minor 3rd and major 7th. (See below)

"Diminished 7th" chord = chord with a diminished 7th interval. This is one semitone smaller than a minor 7th. The chord also has a diminished 5th (and minor 3rd), and is sometimes called a "full(y) diminished" chord.

"Half-diminished" chord = 7th chord with only one diminished interval - the 5th.

E.g.:
Bdim7 = B D F Ab (from C harmonic minor). B-F = diminished 5th, B-Ab = diminished 7th. Jazz symbol B°7.
Bm7b5 = B D F A. Just the one diminished interval, B-F. So only "half" diminished. (B-A is a "minor 7th" interval.) Jazz symbol Bø7, or just Bø. (The "7" is superfluous, because "ø" already says "half-diminished".)

BTW, when we call a chord a "minor 7th", we're actually referring to the 3rd of the chord, not the 7th - even though the 7th is minor too. This is how the shorthand works:

A7 = "A major minor 7th" in full. But chord symbol language takes a major 3rd and minor 7th as default, because those are the most common variants of those intervals. (In the major scale there are five minor 7th intervals and only two major 7ths.) So we can just call it "A seven", knowing the 3rd is major (C#) and the 7th is minor (G).*

Am7 = Here the "m" refers to the 3rd (C). The "7" is the standard minor (10-semitone) 7th (G). Jazz symbol A-7.

Amaj7 = The "maj" refers to the raised (larger) 7th (G#), not the 3rd (which is the default C#). Jazz symbol AΔ. (Think of the triangle as an arrow, raising the 7th.)

Am(maj7) = Now both 3rd and 7th have been changed from the default, so we have A C E G#. Jazz symbol AmΔ, or A-Δ

Like all good shorthand systems, the most common chord types get the shortest names!

* As you may know, this chord type is commonly called a "dominant 7th". That's because it's built on the dominant (V) degree of the scale (major or harmonic minor). I.e., A7 comes from the 5th (dominant) degree of the D major or D harmonic minor scale.
An A major triad is actually the "dominant" (V) chord in those keys. It becomes a "dominant 7th" when (surprise surprise) we add a 7th to it. The 7th (G, taken from the D major or D minor scale) is the smaller (minor) of the two common sizes; and the V degree of the scale is the only degree that produces that major 3rd-minor 7th combination, hence the "dominant 7th" name.

Guitars+gems 05-14-2018 01:53 PM

Yes, you're right, Jon; I was thinking of the chords in terms of stacked thirds, the 2 intervals between 1 and 3 and then 3 to 5, and then another third for the 5 to 7.
Thanks for this. It clears up a lot of nebular thinking I had around the 7th chords. I'm going to print this and keep it in my binder for reference.

ceciltguitar 05-16-2018 03:04 PM

Warning: The following is pure speculation from a person with NO formal academic music education. Read at your own risk

The Bm7b5 chord is enharmonic with the G7th chord played with no root.

If you play the Bm7b5 chord and also include the either or both of the open E strings then the chord is enharmonic with E7susb9.

The Bm7b5 chord is also enharmonic with a Dmin add 6 chord.

The Bm7b5 chord is also enharmonic with a F6 with a b5.

So what chord you are actually playing when you play the Bm7b5 depends on the CONTEXT of the chord progression that you are playing.

Mr. Jelly 05-16-2018 03:19 PM

I use this chord all the time but I play it X2323x and xx2323. I use it all over the neck as it repeats itself every four frets. That is unless I misunderstand what you are saying.

JonPR 05-16-2018 04:46 PM

Quote:

Originally Posted by Mr. Jelly (Post 5730484)
I use this chord all the time but I play it X2323x and xx2323. I use it all over the neck as it repeats itself every four frets. That is unless I misunderstand what you are saying.

x2323x is half-diminished. It doesn't repeat every 3 frets.
xx2323 is dim7, and does.

The dim7 on middle 4 is x2313x ;).

JonPR 05-16-2018 04:50 PM

Quote:

Originally Posted by ceciltguitar (Post 5730478)
Warning: The following is pure speculation from a person with NO formal academic music education. Read at your own risk

The Bm7b5 chord is enharmonic with the G7th chord played with no root.

You mean it's a rootless G9.

"Enharmonic" means the same sound, different spelling - like A# and Bb. In this case the note names are all the same (BDFA).
Quote:

Originally Posted by ceciltguitar (Post 5730478)
If you play the Bm7b5 chord and also include the either or both of the open E strings then the chord is enharmonic with E7susb9.

Again, enharmonic is not the right word. It's just the same chord.
Quote:

Originally Posted by ceciltguitar (Post 5730478)
The Bm7b5 chord is also enharmonic with a Dmin add 6 chord.

It's an "inversion" of Dm6. ;)
Quote:

Originally Posted by ceciltguitar (Post 5730478)
The Bm7b5 chord is also enharmonic with a F6 with a b5.

Yes, but that would be pretty rare.
Quote:

Originally Posted by ceciltguitar (Post 5730478)
So what chord you are actually playing when you play the Bm7b5 depends on the CONTEXT of the chord progression that you are playing.

Yes! :)

ceciltguitar 05-16-2018 08:14 PM

Thanks for the corrections, Jon!

....Mostly rootless.....yeah.....:lol::guitar:

Wags 05-16-2018 09:32 PM

Greg Lake uses it to great effect in “From The Beginning”.


All times are GMT -6. The time now is 12:36 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright ©2000 - 2022, The Acoustic Guitar Forum

vB Ad Management by =RedTyger=