the Dominant-7 chord in major/minor keys

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fretski
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the Dominant-7 chord in major/minor keys

Post by fretski »

I'm trying to complete the bottom right section of the cheatsheet linked below. The vii chord for the major keys is a diminished chord beside which I added he Dominant-7 chord in a next column because it seems to be a pivotally important chord. In the minor keys below it the VII chord is a major chord. How do I complete those lines, with a Dominant-7 at the end?

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Em7, F#m7, Gm7, Am7, Bm7, Cm7, Dm7
?

I find it a little confusing when I read things like the 7 and the m7 additions BOTH mean the addition of a lowered-7; the former to a major triad and the latter to a minor triad. The mod is the SAME, it's the founding triad-label that is different and IT says what gives. Isn't the tag "m7" superfluous then since it is never used the way that the suffix would suggest itself to be added: "Em-m7"?

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I'm adding to this topic a question I had in another thread but which belongs more in here, even if not limited to so called 7 chords. Sticking with the above cited Em chord in the key of Am, what if I want to create the Em7 chord? Is that "7" the 7th note (G) of the Am key scale or the 7th note up from the chord root E which would make it D? Would this Em7 then be the Dominant-7 in the key of Am?
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merlyn
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Re: the Dominant-7 chord in major/minor keys

Post by merlyn »

You're familiar with this :

Image

Seventh chords use the same principle adding another third on the top :

Image

A seventh isn't an 'addition'. You could call it an extension, but I usually call it a seventh :) I reserve 'extension' for 9, 11 and 13. An example of an addition is Cadd9 -- C E G D. contrast this with C9 -- C E G Bb D. The 'add' chord skips over the 7th.
fretski
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Re: the Dominant-7 chord in major/minor keys

Post by fretski »

merlyn wrote: Mon Nov 30, 2020 3:09 pm You're familiar with this :

Image

Seventh chords use the same principle adding another third on the top :

Image

A seventh isn't an 'addition'. You could call it an extension, but I usually call it a seventh :) I reserve 'extension' for 9, 11 and 13. An example of an addition is Cadd9 -- C E G D. contrast this with C9 -- C E G Bb D. The 'add' chord skips over the 7th.

When I see 3 notes on the staff become 4, to my way of thinking something is bein added to the triad :lol: :lol:


Ok, so in Cadd9 we add the 9th to the C major triad, so far I'm still here. An M7 is the addition of the 7th note to the major triad. Both involve the additon of one other note to the major triad, so why the placarding as if they were on different plants? Why not just CM7 and CM9?

In the army they say "all you do is listen until you become at least a colonel, until that time if we want you to have an opinion we will issue you one". Nonetheless it seems to my greenhorn eyes that the entire chord labeling matrix is one huge fubar :D :D

A 6 chord means the addition of the 6th note to a major triad, while a 7 means the addition of a lowered-7th note to a major triad and it is an M7 chord that takes up the 7th note without being lowered, etc. I would think that... no, I'm not going to have an opinion just yet!
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Re: the Dominant-7 chord in major/minor keys

Post by merlyn »

fretski wrote:An M7 is the addition of the 7th note to the major triad. Both involve the additon of one other note to the major triad, so why the placarding as if they were on different plants?
To my ears they are on different planets. :lol:
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Re: the Dominant-7 chord in major/minor keys

Post by lykwydchykyn »

fretski wrote: Mon Nov 30, 2020 3:36 pm
Ok, so in Cadd9 we add the 9th to the C major triad, so far I'm still here. An M7 is the addition of the 7th note to the major triad. Both involve the additon of one other note to the major triad, so why the placarding as if they were on different plants? Why not just CM7 and CM9?
A CM9 includes the 7, whereas a Cadd9 does not. So a CM9 is C-E-G-B-D, while Cadd9 is C-E-G-D. In jazz it's usually C6add9, which is C-E-G-A-D.

IOW, if you just use the number, it's understood that all the intervening thirds are (potentially) part of the chord; but if you use "add", it means just adding that note. So C13 doesn't just add an A, it adds the B♭, D and F as well. Cadd13 would be the same thing as C6.
Nonetheless it seems to my greenhorn eyes that the entire chord labeling matrix is one huge fubar
It's definitely an organically grown thing, built around the functional needs of gigging musicians rather than any theoretical purity. It's important to understand that a lot of the redundancy and overlap is there to communicate context and intent rather than just "which notes do I play". For example, Em7 and G6 are the same four notes, but in one chord "E" is a very important note, and in the other it's just some added color.
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Re: the Dominant-7 chord in major/minor keys

Post by Philotomy »

fretski wrote: Mon Nov 30, 2020 3:36 pm An M7 is the addition of the 7th note to the major triad.
Right, although good to note that it's the addition of a major 7th to the major triad.

Major triad + major seventh = Major 7th chord (e.g, Cmaj7, CM7, CΔ7)
Major triad + minor seventh = Dominant 7th chord (e.g., C7)

Minor triad + minor seventh = Minor 7th chord (e.g., Cm7, C-7)
Minor triad + major seventh = Minor major 7th chord (e.g., CmMaj7, CmM7)
Both involve the additon of one other note to the major triad, so why the placarding as if they were on different plants? Why not just CM7 and CM9?
One reason is because often a chord is not just adding one note to the triad, and there needs to be some way to concisely indicate exactly what notes are being included. And there's the not only the maj/min thirds to deal with, but also maj/min sevenths (as well as augmented/diminished intervals).

In chord construction, you have your triads. When you stack a seventh, you get a seventh chord. When you stack more notes on top of a seventh, you get an extended chord. This is kind of inherent in the way chords are constructed. So if you say "extended chord" to musicians, they'll assume you mean "some sort of seventh chord with extension beyond the seventh." Note that seventh chords, themselves, are not usually considered "extended chords". An extended chord includes and extends on top of the seventh.

So instead of just thinking about "triad plus some notes" you need to think about those three categories, each of which builds on the former: basic triads, seventh chords, and extended chords.

This means that the chords like C9, C11, C13, etc. all mean "a dominant 7th chord with something added": they imply the inclusion of the dominant 7th (the triad + a minor seventh). They don't just add one note to a triad, they add two or more.

And there's also major 9th chords. Those are the major triad, the major seventh, and the 9th. So C9 would be C E G B♭ D, but Cmaj9 would be C E G B D.

In contrast, Cadd9 means "a C major triad with only the 9th added -- don't include the 7th." An add9 chord steps outside the "normal" pattern of chord construction in this way.

So to address your question about why not just "CM7" and "CM9", it's because extended chords include a seventh, and also because we need a way to distinguish between the major and minor seventh intervals, as well as the major/minor third in the triad. And because it's possible to add a 9th (for example), without including a seventh. The somewhat convoluted naming convention of chords allows you to specify all of this once you know its "rules."

Under those rules, "CM7" means "a C major triad with the major seventh". "CM9" means "a C major triad with the major 7th and the 9th". If you want to specify "C major triad with an added 9th" you use "Cadd9" to indicate that it's only adding the 9th and not building on the seventh chord. If you want a dominant 7th chord with an added ninth, that's "C9". And so on.

Sixth chords (e.g., C6) are not considered "extended chords" because they do not build on top of a seventh chord (they don't "extend beyond the seventh"). They're really "add chords" like the "add9".
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fretski
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Re: the Dominant-7 chord in major/minor keys

Post by fretski »

lykwydchykyn wrote: Mon Nov 30, 2020 7:53 pm It's definitely an organically grown thing, built around the functional needs of gigging musicians rather than any theoretical purity. It's important to understand that a lot of the redundancy and overlap is there to communicate context and intent rather than just "which notes do I play".
I can both accept and live with that, for a while anyway :lol: :lol: :lol: :lol:
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Re: the Dominant-7 chord in major/minor keys

Post by merlyn »

fretski wrote: Would this Em7 then be the Dominant-7 in the key of Am?
Nay, nay and thrice nay. Run around the parade ground ten times repeating "a dominant has a tritone, a dominant has a tritone." :lol:

What you could do is familiarise yourself with intervals. Twelve intervals within an octave. Play them, then categorise them as consonant or dissonant. Which intervals are consonant (sound good or at rest)? Which intervals are dissonant (sound bad or want to be resolved)?
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