# Using standard Roman numeral analysis how should 7th and 9th qualities be determined?

Example:

`C: V7` or inversions like `C: V6/5` are understood to be dominant-seventh chords and `C: V9` a dominant ninth chord with a diatonic, major ninth.

I think the basic idea is all the Arabic numeral parts are understood to be diatonic relative to the root indicated by the Roman numeral.

`V9` in `C` major the root of `V` is `G` and the 9th above that root is `A` which is a major ninth.

By comparison `iii9` in `C` major the root of `iii` is `E` and the 9th above that root is `F` which is a minor ninth.

That seems clear enough, but what about when the Roman numeral symbol indicates a chromatic chord?

Examples:

`C: V9/ii` or `Am: I7` or `C: iv9`

When secondary or borrowed symbols are used I understand that we are temporarily referencing a new tonic/key and I sort of expect the Arabic numerals should then be relative to the temporarily referenced tonic/key.

If that is way it should be done, I get these examples...

`C: V9/ii` is a secondary dominant relative to tonic/key `Dm` and `V9` in `Dm` would get a minor-ninth. So the chord `C: V9/ii` is `A C# E G Bb`.

`Am: I7` is a borrowed chord relative to parallel major `A` major and `I7` in `A` would get a major-seventh. So the chord `Am: I7` is `A C# E G#`.

`C: iv9` is a borrowed chord relative to parallel minor `Cm` and `iv9` in `Cm` would get a major-ninth. So the chord `C: iv9` is `F Ab C Eb G`.

I think the confusion is when using secondary or borrowed chord the RNA symbol isn't relative to the key denoted by the colon `C:` , `Am:`, etc. but by the secondary slash or switching of upper/lower case which indicates a temporary tonic/key or mode change from the key denoted by the colon.

...is this correct?

• The first half of this is a great question, but I didn't really get your examples; what do you mean by relative? Commented Mar 28, 2019 at 16:44
• 'iii9 is Em9' spelled E G B D F? Yes, diatonically, but surely a m9 rooted on E is E G B D F#? And 'C iv9 is relative. Isn't it parallel?(Same as Am: A maj.) I appreciate this question was not easy to put together!
– Tim
Commented Mar 28, 2019 at 16:56
• @Tim I think `iii9` is `Emb9` rather than `Em9`. It's hard to not be wordy, but my question/suggestion is RNA is diatonic and jazz symbols aren't - to me the jazz symbols are all relative to a dominant chord and its extensions in a major key. Commented Mar 28, 2019 at 17:08
• @Shevliaskovic, relative to a tonic/key. Ex. `V` surely that is relative to something or else you wouldn't be able to know the specific notes to play. Let me try adding some edits in my final three examples. Commented Mar 28, 2019 at 17:10
• @Michael: could you post an example of literature? I‘m not sure whether I understand your question. Do you mean that if we are in am and A7 occurs as V7/D it would be unclear whether in RNA was I7 or V7? And if one analysis I7 would this mean a minor or a major 9th? Commented Mar 30, 2019 at 6:42

There are multiple variants of RNA in common use. The distinguishing styles V, v, V+, v° will be readily recognized as symbols for major, minor, augmented, and diminished triads over a root that is a diatonic scale degree (for a chromatic root, a prefixed accidental must be used, as ♭II6 for the Neapolitan sixth).

However, there seems to be no similarly standard convention for distinguishing qualities of 7th and 9th chords, apart from vii°7 and viiø7 for diminished and half-diminished 7th chords respectively. The most sensible convention is to style the Roman numeral according to the quality of the underlying triad and assume the added notes are diatonic unless indicated otherwise, for instance

• C: iii9 is E-G-B-D-F (= Em7♭9 in jazz notation)
• C: V9/ii is diatonic in the key of ii, i.e. A-C♯-E-G-B♭
• C: I7 (or IM7, etc.) is a major seventh chord; C: I♭7 or Idom7 is a dominant seventh chord (a.k.a. V7/IV, but with different functional implications)
• C: iv9 is F-A♭-C-E-G, a perfectly normal mixed-mode chord.

In minor keys the picture is muddied by the presence of multiple variants of the 6th and 7th scale degrees. Unfortunately for the standardization-minded, a: VII (G-B-D) and a: vii° (G♯-B-D) are in common use. Musically, 7ths and 9ths of chords tend to be drawn from the natural minor scale because they typically resolve downward. Therefore, I'd interpret a: i7 as a minor seventh (common in sequences) unless clearly written otherwise, e.g. a: i♯79 (sorry I can't make the numerals vertically aligned).

• `Idom7` seems like a jazz oriented RNA mod, `V7/IV` is the usual, functional RNA symbol. Commented Apr 17, 2019 at 13:32
• `Cm:iv9` would be `F Ab C Eb G` so shouldn't the borrowed chord `C:iv9` be the same set of notes? `F Ab C Eb G` Commented Apr 17, 2019 at 13:34
• @MichaelCurtis I saw Idom7 in Aldwell & Schachter for the first chord of Beethoven's 1st Symphony. The point they were making is that the chord, in addition to being V7/IV, can be retrospectively heard as a modified tonic. Commented Apr 19, 2019 at 15:31
• @MichaelCurtis And as to C:iv9, changing the case of the Roman numerals is not the same as moving to the parallel mode (e.g. C:III would be E major, different from Cm:III) so I feel justified in saying that only the third of the chord is affected. Commented Apr 19, 2019 at 15:34
• That's an interesting point about `C:IV` versus `C:iv`, the later I understand to mean borrowed chord rather than "lower the third." Commented Apr 19, 2019 at 15:53

I assume this question is developed from recent questions concerning accidentals whether they are chromatic or diatonic.

It is a question concerning analysis and different analysis systems : RNA and analysis of Jazz/Pop.

In Jazz - and the Riemann/Maler system would be no confusion while in the RNA you have to decide for modulation or not. If your analysis is continuing in the new key the (V7) are minor 7th and (V9) are minor when they are secondary dominants to ii,iii and vi degree.

If your not changing the key in your analysis there will be no confusion by adding a small flat in front of the 7 in case of I becomes a secondary dominant to IV (as in Jazz the V7b5).

• Yes, the question is about RNA and specifically about temporary chromaitic harmony, not modulations, so how to understand 7 and 9 figures when the RNA is a secondary chord or a borrowed chord. I gave examples to illustrate both cases. Commented Apr 15, 2019 at 16:33
• I understand your last sentence about adding accidentals - sort of cautionary accidentals to numeric figures as a kind of imitation of jazz or figured bass, but the question is specifically if RNA always assumes diatonic intervals which are diatonic to the relative/temporary tonic. Commented Apr 15, 2019 at 16:37