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C7 is a dominant 7th chord.

G or G7 is the dominant chord of the C-major scale.

Is the word dominant related between these two?

The word "dominant" relates to several items in music. In Common Practice Harmony, the 5th scale degree is called the Dominant. In a Major scale, the 4-note chord build on this note (stacking thirds) is a Major-Minor Seventh commonly called a "dominant" chord. (Major-Minor here describes the quality of the third and seventh of the chord, respectively.) The C7 chord has the same set of intervals as other Dominant-Seventh chords and is thus called a "Dominant Chord." In one case, there is a reference to the 5th scale degree and in the other, there a reference to the interval pattern of a chord.

Why is a C7 chord named a dominant seventh chord?

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    It means both. Like many words both in music and English in general, "dominant" has different meanings in different contexts. Commented Apr 3, 2017 at 21:19
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    It's worth noting that the naming of the dominant seventh chord happened before dominant seventh chords were used much outside of literally being a dominant chord (resolving down a fifth). In the modern day, we use seventh chords all the time, even when they don't have this function (the D7 at the beginning of taxman by the Beatles has no dominant funciton), but we still call them dominant seventh chords because that's what they've always been called. It's kind of like how we still say "dial" a number even though phones haven't had "dials" for years!
    – Some_Guy
    Commented May 4, 2017 at 13:57
  • it actually has both as @Todd Wilcox put it. To expand on that, there is "dominant" wherever there is a "7nth", and there's a tonal dominant which could simply be a triad. The whole jazz genre, if you will, depends on the first defintion, that is, maintaining harmonical structure on the brink of tension for prolonged periods of time. Commented Feb 2, 2021 at 1:43

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A dominant is a very specific idea in functional harmony. The dominant's job is to take you back to the tonic. Why a dominant has so much pull in functional harmony is that a dominant chord utilizes the leading tone along with having the common tone with the tonic chord which is the dominant itself.

In terms of scale degrees the dominant is the scale degree where you build chords that tonicizes the tonic of that scale. Naturally, when you build a 7th chord off of G in C Major you get a G7 which by no accident is known as a dominant 7th. A C7 is a dominant chord and its job is to take you to the tonic of F or tonicize F.

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  • "A dominant is a very specific idea in functional harmony. The dominant's job is to take you back to the tonic" I disagree somewhat with this. This to me is more a function of the major seventh, which the Dominant chord usually has, but there does exist unusual keys with minor sevenths in the dominant that sound different.
    – Neil Meyer
    Commented Jul 27, 2016 at 14:31
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    @NeilMeyer - what? A dominant chord DOES NOT have a major seventh in it. A dominant chord, by definition, has 1, maj 3, P5 and min7 notes . There will never be a major 7 note in there. Unless you're confusing the major 7th note of the tonic, which will manifest itself as the major 3rd of the actual dominant chord. A minor 7th chord will comprise 1, m3, P5 m7, which will be called just that. Minor seventh.
    – Tim
    Commented Jul 28, 2016 at 11:29
  • @Tim he means the leading tone i.e. the major seventh degree with respect to the tonic
    – Some_Guy
    Commented May 4, 2017 at 12:56
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I'm not 100% sure what you're asking, but:

  • Yes, C7 is a dominant seventh chord. This doesn't necessarily mean that it is the dominant, just that it is the same "quality" (ie, the same make-up) as a dominant seventh chord, which is a major triad with a minor seventh.
  • G is the dominant chord of C major

This means that G7 is the dominant seventh chord of C major.

The dominant is always a perfect fifth above its tonic. This means that a dominant seventh chord will always have some urge to resolve down a perfect fifth. Although G7 is the dominant of C, a C7 can still appear in C major, but it will want to resolve down a perfect fifth to F. (It doesn't have to, but it wants to!)

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The description "Dominant 7th" is used in two ways. It can mean any major triad with added minor seventh. Or it can mean the ACTUAL dominant 7th chord in a given key.

If we're in C major, G7 is the dominant 7th chord of the key. But D7, A7, Bb7, F#7... are all "dominant 7th" type chords. (And yes, all those chords can exist in a piece of music in C major).

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“I Am Confused About Dominant.”

At first, this is not an easy concept when you have a seventh in the fifth of a scale and a 7th is the seventh chord as well. After a formal class in jazz theory, I got it. I will try to answer your question.

We’ll use the C scale. The seventh note in C is B. It is the seventh note, seventh chord, but we are talking about the fifth of the scale, specifically the 7th note of the fifth chord of a scale. The seventh note of the fifth can make the chord either a Major 7 chord or a dominant 7 chord.

The seventh in a dominant 7 CHORD refers to the notes in the chord. Stack the chord in thirds. like this, C E G B, or 1, 3, 5, 7. The seventh note of the C Chord is B. In C Major 7 the scale is exactly that, C E G B. If you flatten the 7th note, the chord becomes C E G and B flat. It is a dominant seventh chord when you flatten the 7th note in the chord. Dominant 7th chords are the fifth in a Major scale with the formula C E G Bb. In C that is G7. In F, it is C7. It is sometimes referred to as the V7 Chord to distinguish it as the fifth and not the seventh of the scale.

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Some of the answers seem to add to the confusion!

The dominant chord in a key is so called as it is a pushy sounding chord. It tends aurally to want the tonic chord to follow it. No, it isn't always the case that the tonic comes next, but that's part of the tension that music can bring. You expect one thing, and something different happens.

The dominant seventh chord has an extra note to the triad of 1,3 and 5. The sequence is followed, so it's a 7. That's where confusion sets in. It's not the 7th of the scale that the dominant chord would be the key of. In other words, G7, as a dominant of C, would have F natural as the 7th part of it. Not F#, which is the 7th of the G scale.

That's because G7 - a.k.a. G dominant 7th - is a chord from the C key, not its own G key.I know that sounds adaft, as we find G7 in lots of songs that are in G. However, most times, the following chord is C (or Cm), so the G7 needs the 7th part of it to be from key C rather than its own key,G.

Musically, what's happening is the 3 is a semitone below the tonic root, and the 7 is a semitone above the tonic 3. To resolve, they both move a semitone each, the smallest change possible, and everything sounds fine again. The tritone - very unstable sounding - resolves to a nice major (or minor) 3rd interval.

So, in summary, the dominant 7th chord has all its notes from the tonic it's pushing to, as in E7 has a D as its 7th, even though the key of E has D# in it. It has become part of the tonic it's aiming for, so needs a D natural.This 7th can also be called a m7 or b7 of the dominant's own key.

I was hoping to uncomplicate the concept, but it's not a particularly simple answer after all!

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In counterpoint studies, which study the musical practice before the notion of "everything comes from harmony" posed by J.P.Rameau, a dominant was simply a note that was most often used throughout the melody.

As I recall.

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    I'm not sure which bonehead downvoted you, but you are indeed correct, although I thought the source was J.J. Fux. So, historically, the 5th of most modes was the most used note and hence termed the 'dominant' note in many melodies. And chords built off of the 5th are therefore named dominants. And to the point of the OP, the only chord built off of a major scale, having a major 3rd, perfect 5th and flat 7th is a seventh chord built off of the 5th degree or dominant.
    – yamex5
    Commented May 3, 2022 at 6:13
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In a more literary definition, the adjective dominant, as applied in music, details that the function of whatever structure it describes sets up a resolution to a structure with a tonic function. Generally, for chords and scales, dominant will mean one of two things:

  • The chord or scale described contains both a major 3rd interval and a minor 7th interval. For example, a C dominant seventh chord (C7) has both E and B♭ in it, hence the name "dominant". It resolves easily to an F major chord, which has tonic function. Also, scales based off of a dominant chord will usually be called dominant scales.
  • The chord or scale described is constructed from the (perfect) fifth degree of a scale. This is based off of the names for scale degrees where 1-2-3-4-5-6-7 as scale degrees become Tonic-Supertonic-Mediant-Subdominant-Dominant-Submediant-Subtonic(or leading tone if a semitone below the tonic). Notice that the fifth degree is named "Dominant". Thus in any mode, the chord built off of the fifth is called the dominant, regardless of whether it actually contains the ♮3 and ♭7.

So: The word dominant has two meanings in music: It can describe the quality of a structure, or the types of intervals found within it; or it can describe the function of the structure it describes.

(Confusingly, The two meanings are not always the same, as certain chords can have dominant function without being of the dominant seventh quality, and vice versa. The most common instance is where they are in conjunction: In B major, an F♯7 chord earns the moniker "dominant" for both reasons: Its interval qualities of the ♮3 and ♭7, and its construction upon the 5th, or dominant, of the key B major.)

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