# Is secondary dominant in fact resolving V chord of major scale with I chord of different mode?

I just saw the chord scale of five of four. It used C mixolydian chord scale.

So 'IV' of five of four is the F Major scale, and the target chord is F Lydian chord scale.

Does that mean I chord from F Lydian scale is resolving V chord from F Major scale?

• What do you mean by "chord scale"? Apr 17 at 0:53
• In the book "the Berklee book of jazz harmony" the author shows a scale that a chord is based on. So it has T9, T11, T13 in 2, 4, 6's place. ii chord shows D Dorian, iii chord shows E Phrygian and so on...
– Sean
Apr 17 at 1:09
• I don't know what T9, T11, and T13 refer to; that notation must be specific to the book. Also, what is meant by "the target chord is F Lydian chord scale". Apr 17 at 3:11
• It might be helpful if you quote the book directly; even better if there's a notated example you can post. Apr 17 at 3:12
• @Aaron In Berklee speak the T refers to tensions, the notes beyond the 7th degree. T9=2, etc. Apr 17 at 3:50

Your terminology is a bit off and I’m not sure I understand your question completely so I will offer you an explanation as best I can and hopefully it will be satisfactory. If not feel free to follow up in comments.

You are in the key of C major. The I is a C chord and the IV is an F chord. IV is a chord, not a scale. You can play F Lydian scale over the F (IV) chord. The parent scale for F Lydian is C major (Ionian), the home key.

A V/IV is a C or C7 chord. This is a non-diatonic chord and a C Mixolydian scale will work over this chord because it is dominant. The V/IV chord has a C root, which is the tonic of the key of C. That basically means a V/VI is also a I or I7.

The V/IV C7 chord comes from the key of F since you are resolving to an F chord. Thus when you play a C Mixolydian scale the parent scale for that scale is F major (Ionian).

EDIT: One thing that jazz players often do is add upper structures to chords, like 9, 11 or 13 for color and embellishment purposes. The reason I mention this is that very often a #11 is added to major 7th or 6/9 chords regardless of whether they are a I or a IV or any other chord. The #11 note makes the scale you would play over that chord a Lydian scale but that does not mean you are playing in Lydian mode, the Lydian scale only applies to that specific maj7 or 6/9 chord.

• That's my read of the question, too. Apr 17 at 3:53

Trying to make sense of the terminology used in the question, I guess it's about modes, so this answer will be with reference to them.

The key used in the question is F, so that's F Ionian. The fifth mode of key F is C Mixolydian. All the modes from parent key F will have all naturals, except B♭.

That's where chord C7 comes in - the m7 part of it is B♭. It's not, as many believe, part of key C, diatonically - it can't be, as the 7th note there is B♮, producing, amongst other chords, Cmaj7.

F Lydian? That's a mode of parent key C. With B♮, not B♭.So V of F Lydian is not the true dominant chord leading to I (Fmaj).

So I think OP's confusion is not comprehending the parent keys - but knowing the ttsttts or whatever makeup of each mode. That's why I feel it's important to be aware of the former at least as well. It makes the theory sit better note-wise.

There's also the confusion between, say, F Lydian, and the Lydian of F - two different sets of notes, which may be a contributory factor in this question.

• Tim, I think you’re off base here. He mentions secondary dominants and V/IV and identifies F as the IV in the second paragraph. Apr 17 at 15:12

I just saw the chord scale of five of four. It used C mixolydian chord scale.

Assuming the key is C and that secondary dominant progresses to "target" the progression is:

C7         F
(C,E,G,Bb) (F,A,C)
C: V7/IV      IV

In the chord/scale system the basic scale for a dominant seventh chord is a mixolydian scale and the basic scale for a plain major triad is a major scale. So, you would play C mixolydian then F major scales.

So 'IV' of five of four is the F Major scale, and the target chord is F Lydian chord scale.

The Roman numerals for what you wrote would be IV/V/V. In English that reads "the subdominant of the dominant of the dominant" of some not specified starting key, but the apparently desired end result is an F major "chord/scale, which I will simply say should be an F major triad, because that is actually what IV represents, a major triad on some chord root. So, we get...

IV/V/V
Bb:  F C F

In English that reads "The dominant of Bb major is F major, the dominant of F major is C major, and the subdominant of C major is F major." Which is redundant, because you could simply write Bb:V to get an F major triad.

I think that particular sentence must be a miswording of some original source text.

Does that mean I chord from F Lydian scale is resolving V chord from F Major scale?

F lydian: I = triad F major = chord tones F,A,C

F major: V = triad C major = chord tones C,E,G

As a resolving progression, that makes sense, that would mean the V comes before the I, and so as a progression of "scales" (which really does not makes sense, chords progress to chords) it would be...

F major: V to F lydian: I

But that is really confusing, and is not how I understand the "chord/scale" system to work. It mixes up "chord/scale" and Roman numeral analysis. When a jazz chord letter is given, like F, F gives us both the chord root and the "tonic" of some scale, the mode of which is determined by reading the full chord symbol. The implicit understanding is the letter is always referring to an ostensible I chord in some scale/mode.

If you want to express progression F:V I through the use of scales, and you want that V to be expressed as a dominant, the jazz chords should be written C7 F. If not, and you write simple triads C F, the "chord/scale" system will ambiguously suggest playing scales C major followed by F major which will not provide a dominant feel to the F major chord.

All of this is greatly simplified by simply expressing the progression with an appropriate local key. Just write F:V I and play in F major. That's one key, one scale, no secondary dominants, no changing modes.