Beginner impro Why are dominant 7th chords called dominant?

[cappers]

I am trying to get my head around chords!

I think I understand Major 7th construction: major chord arpeggio 1,3,5 + 7, whereas the Dominant 7th has a flattened 7th so 1,3,5 + 7b.

CMaj7: C E G B ->** EDom7: CDom7 or more correctly C7: C E G Bb (Thanks @PiccoloPirate)
DMaj7: D F# A C# -> DDom7: D F# A C
EMaj7: E G# B D# -> EDom7 E G# B D
etc

My question is why is it named 'dominant'? I believe the 7th is a 'leading tone', so is the 'dominance' the fact that it needs to resolve down to sound correct? Also can it resolve up instead?

Thank you.

** edited to correct typo

 

[skeller047]

My question is why is it named 'dominant'? I believe the 7th is a 'leading tone', so is the 'dominance' the fact that it needs to resolve down to sound correct? Also can it resolve up instead?

The naming of the dominant note/chord/sound is answered above and I will only add that names are kind of arbitrary and historical reasons for them may have been lost or obscured by time.

Regarding leading tones - the 7th degree of a major scale is the "leading tone"; being a half step under the root, it wants to lead up to it. The 7th degree of a dominant chord is NOT the leading tone, it is the 4th degree of the associated major scale, and wants to lead down to the 3rd. Example:

• G7 is the dominant chord of C major
• B is the 3rd of that chord, and leads up to root of C
• F is the 7th of that chord, and leads down to the 3rd of C

Note that B and F form a tritone (AKA diabolus in musica, "the devil in music"), which is sonically dissonant. These tones are considered unstable and "want to resolve".

Normally they resolve as described above, but they just as easily can resolve the opposite way - B DOWN to A# and F (E# really) UP to F#. B and E# are the 7th and 3rd, respectively, of a C#7 chord, which is the dominant of F# major.

The above is one way to quickly modulate to an unrelated key, and is also why the concept of "tritone substitution" works so well. In other words C#7 can substitute for G7 in a progression (and often does). People teach that the "tritone" involved is the relationship between the roots (G and C# being a tritone apart), but the reason it works is the 3rd and 7th of those two chords, the very notes that give the chord its character, are the same, and can function properly in either key.

A good way to get this concept is to play on a keyboard, with the notes B and F in the right hand, and the left hand playing either G or C#. Then the right hand notes move to C and E, and the left hand moves to C. Both G plus B and F, or C# plus B and F, resolve with the same sense of finality.

 

[LostCircuits]

I think you have the right of it, IMO "dominant" is just jargon and trying to shoehorn its common definition into the V resolving to the I is going to get loosey-goosey.

That said I agree with @LostCircuits take that the 5 of the chord tends to stand out, at least for my ears. But then what about inversions? 😀

In the inverted chords always the highest note stands out, at least that's what I just got trying it on my keyboard / piano.

 

[Tenor Viol]

Historically, the 'dominant 7th chord' was precisely that - a 7th chord built on the dominant. So, in Cmaj that would be GBDF and by definition the F is an F natural as it's Cmaj. In that case it is thus a minor third on top, which could be described as a chord of G with a b7... which tends to be how it gets described, which is not strictly speaking correct.

It also means that each key has only ONE dominant 7th chord as there is only one dominant in any key base don the dominant i.e. the fifth note of the scale.

But... people tend to refer to any major chord with a b7 as a "dominant 7th chord".

Its function in traditional harmony is to resolve to the tonic.

 

[Pete Effamy]

I’ll say this @cappers :

Don’t take these first steps / “rules” of harmony to be THE rules that shalt not be broken.

I gained a lot of preconceptions at college about what shouldn’t happen in music, whereby they were only meant (or should have been) as a general guide that will definitely work and sound great, just like lots of other tried and tested music over hundreds of years.

Stuff like not writing consecutive 5ths or octaves between two parts has long been ignored and the use of non-functional harmony doesn’t mean that the music will sound “out there”, or that the sky will fall in.

Learn this stuff as great stuff, but it’s a starting point.

 

[Pete Effamy]

Answered your own question”question “

 

[Pete Effamy]

But... people tend to refer to any major chord with a b7 as a "dominant 7th chord".

Its function in traditional harmony is to resolve to the tonic.

Answered your own “question “ - music evolves

 

[cappers]

I’ll say this @cappers :

Don’t take these first steps / “rules” of harmony to be THE rules that shalt not be broken.

I gained a lot of preconceptions at college about what shouldn’t happen in music, whereby they were only meant (or should have been) as a general guide that will definitely work and sound great, just like lots of other tried and tested music over hundreds of years.

Stuff like not writing consecutive 5ths or octaves between two parts has long been ignored and the use of non-functional harmony doesn’t mean that the music will sound “out there”, or that the sky will fall in.

Learn this stuff as great stuff, but it’s a starting point.

I wouldn’t get bogged down in why the terms are so-called. Whilst their original “function “ hasn’t changed and provide a great basis for music theory the musical rules of 500 years ago have been eroded.

Thank you @Pete Effamy.
Yes, rules are to be broken but first one needs to know them!

Not bogged down in nomenclature, just fascinated. As a retired academic I like to know the how's why's and wherefores of things I'm studying. Might be beyond me now but it'll sink in. A few months ago I didn't know a crotchet from a quaver, a tone from a semitone or a sharp from a flat!

 

[Pete Effamy]

Thank you @Pete Effamy.
Yes, rules are to be broken but first one needs to know them!

Not bogged down in nomenclature, just fascinated. As a retired academic I like to know the how's why's and wherefores of things I'm studying. Might be beyond me now but it'll sink in. A few months ago I didn't know a crotchet from a quaver, a tone from a semitone or a sharp from a flat!

I hear you, but it’s a VAST subject and you’re asking some pretty wide-ranging questions already.

Try and sit at a keyboard when you read about harmony so that you can get the theory associated with the sound and the graphic representation (and beauty) on the keyboard of voice-leading

 

[mizmar]

I like to know the how's why's and wherefores of things I'm studying

In addition to what Pete Effamy said, keep in mind that although a lot is this stuff it explained and talked about as eternal truths; it's not. It's great stuff, built over the years by some people at some time and place....

 

[cappers]

My wife says I can be like a dog with a bone; when something really gets my interest I tend to jump in and get somewhat obsessive about it.

Studying and learning to play music at this (late) stage of my life has given me so much enjoyment I can't believe it. I knew it would be hard and require lots of effort and dedication but I'm loving it.

The fact that I can now play (not very fast or eloquently) Bye Bye Blackbird, Summertime, Autumn Leaves, Fly Me To The Moon, Falling in Love With You, Suicide is Painless (MASH), La Mer (current fave!), read simple music notation and produce a noise that doesn't sound like a cow in extremis or a duck with laryngitis, amazes me. Not meaning to sound boastful or glib, just so happy with how it's going!

Icing on the cake.....the local community band - The Saltdean Jazz Band - have invited me to join them at weekly rehearsals and potentially some gigs when I get up to speed (literally!).

 

[mizmar]

a dog with a bone

Not, we hope, in the American slang sense...

 

[LostCircuits]

Not, we hope, in the American slang sense...

But it was his wife who said this.... don't try to be coy now!

Or verklempt!

 

[Pete Thomas]

the 5 of the chord tends to stand out, at least for my ears. But then what about inversions?

The 5 of a chord is not related to or relevant to inversions though. However you voice a C chord, whatever note is in the bass or melody, the 5 is G. I don’t hear it as standing out and I don’t think think that’s the meaning of dominant in this case.

In fact the 5th is the least important note in a chord and can easily be left out of piano, gtr or section chord voicings.

 

[Dibbs]

I think the term dominant comes from plainchant where much of the text is sung on one note and that note is usually the 5th of the mode. So that note dominates the melody in the sense that it's the most common note in the tune.

I don't know for sure. It's something my Dad told me. He was a church organist and choirmaster.

 

[Colin the Bear]

A penny dropped for me when I learned that Cmaj7 is in key of C but C7 is in key of F.

It takes a while when starting out to realise that terms in music have nothing to do with anything else you know. Your maths brain is affronted by a fourth plus a third being a sixth.

The idea of dominant and subdominant are useful to remind you of the way home when soloing or to let the rhythm section know you're not done and you're going again.

 

[Dibbs]

A penny dropped for me when I learned that Cmaj7 is in key of C but C7 is in key of F.

...

Absolutely. It's far too often taught that the dominant seventh has the seventh note flattened. It should be taught that the dominant seventh is the seventh chord formed on the 5th (dominant) of the scale. It's also good to point out that it contains all the scale notes NOT in the tonic triad.

 

[Nick Wyver]

Absolutely. It's far too often taught that the dominant seventh has the seventh note flattened. It should be taught that the dominant seventh is the seventh chord formed on the 5th (dominant) of the scale. It's also good to point out that it contains all the scale notes NOT in the tonic triad.

I must be misunderstanding something.
Tonic triad: C E G
Dom 7: G B D F
Seem to be missing an A.

 

[cappers]

I must be misunderstanding something.
Tonic triad: C E G
Dom 7: G B D F
Seem to missing an A.

Glad it’s not just me. Thought I’d understood but that’s confused me.

 

[Colin the Bear]

Subdominant FAC

I IV V7

All the notes and in the right order.🙂

 

[LostCircuits]

A penny dropped for me when I learned that Cmaj7 is in key of C but C7 is in key of F.

One of my favorites is "Just the Two of Us" chord sequence for the bridge:
For example in the key of D:
Dmaj7 - C#7 - Cmaj7 - B7 - Bbmaj7 - A7 and resolving to F#min
It's a really nice alternating sequence between dominant and maj7 chords and reading the chord sequence, one might expect a chromatic walk down but it is anything but.