Piano World Home Page Forums Our Most Popular Forums Piano Teachers Forum Are all 9th and 11th derived from Dominant 7th?

I watched an instructional video online.

He plays G note with his left hand, and on his right hand D major chord. He claims that it's a G9.

Now if a G9 is derived from a G dominant 7, the F natural note will represent the dominant 7th, meaning the F# would be cancelled, thus preventing a D major chord has a F#.

So a G on the left and a D major chord on the right, is it a G9 ?

I would not describe this as a G9, no.

Rather as:

Gmaj7/9

or:

D/G

or:

G[triangle]9

A G note in the LH and a D Major chord is a D/G. It isn't really a G chord at all if there's no B in it.

Yes, I agree that this is the best description of that chord, which is certainly a woefully inadequate example of a 'G9' chord.

I would call it a G Major 9, and not a G9. G9 should imply a dominant chord. Unfortunately this is put in to practice so inconsistently, that it's almost not worth complaining about.

Kreisler, about your missing B, I'll quote you from another thread: "voicing is an art" Jazzers have a thing for the 3rd and 7th, but that doesn't mean everyone has to do it like that. If I want to leave out the 3rd in my voicing I will For that matter, I might choose to voice a GMaj9 with a single note: the root.

No, it is not a G9.

Chords constructed of 3rds are called tertian chords. To create a 9th chord you add a note to a 7th chord that is a 3rd above the 7th, which is the 9th. The 9th degree is actually the same note as the 2nd but it is an octave higher. A 9th chord is an extended chord because it has a note that is more than an octave from the root. To create an 11th chord you would add the 11th note from the root, and to make a 13th chord, add the 13th note. That is as far as we can go because the 15th note is the same note as the root. A 13th chord is a very big chord. It contains 7 notes. It has every note in the scale in it.

It is not easy to play all those notes so we usually leave out the lower notes in extended chords, but they really need the root note in the bass.

The notes in a G9 chord are GBDFA (add CE to make a 13th) You could leave out the bottom notes and play DFA. That is a Dm chord. So a Dm chord over a G bass note is the same as a G9. And a Dm7 over a G bass is the same as a G11. Dm over G is known as a slash chord because it is written Dm/G

To complicate things a little more any note in a chord can be altered to create an altered chord. So you could have a major 7th interval instead of the minor 7th. This would give you the same as D/G. Altered chords usually have the alteration in brackets after the chord. This could be written G9(maj7)or G little triagle 9

I know an easier way to identify the chord is a D/G. But you have to study the context of the question.

The instructor is trying explain that one can always modify a 7th chord to a 9th chord, by not having to count, but simply add a major chord on the 5th note of the original triad.

In the case of G, the 5th note is D. So instead of counting 7th, 8th and 9th, use slash chord technique and add a D major chord to the 5th note of G. And he claims is a G9. But the doubt that lurks behind my mind is if it's a G9, it implies G dominant 9, which necessitates the inclusion of a F natural.

Your doubt is well-founded. The lowered 7th is always assumed in chord extensions, whereas the major 7th should *always* be specifically indicated.