# What is the correct Roman numeral notation for use in modal pieces?

Looking at a lead sheet (Scarborough Fair), it is noted that the key signature is D major. On closer inspection the song appears to be in Dorian mode. I am guessing that the better approach when e.g. referencing the chords in this case, by Roman numerals would be to refer to them as per the key signature, that is to say the V chord ‘A’ does not become a IV chord, or the I ‘D’ chord become the VII simply because it is in Dorian mode, as this would be too confusing.

I shall be glad for any clarification here.

Many thanks.

Since writing the above, and reading the helpful information I found this link, which may be of interest to anyone, who like me may be unclear about what a tonic is in terms of modal scales.

What is the tonic of a musical mode?

• Wait, is the tonic of your sheet music E, D, or what? If it is E, then you do indeed call the A chord IV and the D chord VII. If it is D, then a key signature of 2 sharps is a poor choice, IMO, because there will be a lot of accidentals cancelling out those sharps. Commented Feb 12, 2020 at 11:01
• Posting a copy of the said music will be useful.
– Tim
Commented Feb 12, 2020 at 11:43
• I only know the song of S&G:Do you mean this tune? www. .com/sheet-music/9970-england-scarborough-fair.html .... but if I read the answers there seems to be a different tune. Commented Feb 12, 2020 at 14:18
• @Dekkadeci: I didn't understand your comment in the beginning. But now I have found the song and tried to give an answer, your comment is quite clear to me: The signatur is D but the tonic is E as it is in dorian of D. this makes sence! And you could give a short answer: tonic = E, A =IV and D=VII Commented Feb 12, 2020 at 16:21

Roman-numeral notation is relatively standard, and to determine any given Roman numeral you need two things:

1. The scale degree of the root of the chord. (This demands knowing what tonic is.)
2. The quality of that chord.

Thus it doesn't matter what mode you're in, only what tonic is. If you're in E Dorian, E is tonic, and therefore an A chord is built on scale-degree 4. If that A chord is major, then this is a IV chord. But the B-minor chord, built on scale-degree 5, would just be v. A D-major chord, built on scale-degree 7, would be ♭VII, and so on.

• I'm confused - probably under-sugared ;) If we are in E Dorian there is the signature of D major / b-minor, true? Is this the same mode as the Dorian of D? (s. answer of Tim) Commented Feb 12, 2020 at 14:50
• The community seems not to be clear or agree about the VII degree, whether the R.N. of VII will need a flat or not ... Commented Feb 12, 2020 at 16:03
• @AlbrechtHügli D Dorian to me implies "Dorian with a tonic of D." "Dorian that uses the D-major key signature" would indicate E Dorian. As for the VII, you're correct; I should have been more specific and used ♭VII. Commented Feb 12, 2020 at 17:01
• Many thanks - So, it is the tonic of the piece rather than the tonic for the key signature that determines the Roman numeral values, thus E Dorian: E F♯ G A B C♯ D E - i ii ♭III IV v vi° ♭VII. I am indebted to your kindnesses. (Seems I can’t do tabs) Commented Feb 12, 2020 at 22:26

The key signature here seems to be a red herring - and inaccurate. If the tonic is indeed D, then it may well be that the key sig. ought to be that of the parent key - C (No ♯/♭). And that doesn't dictate the tonic is C. The tonic is the note/chord where a piece appears to be at rest, at home. So, in this case, D.

Dorian is a minor key (with m3), so tonic is designated 'i'. Therefore here, Dm=i. The dominant chord in Dorian is alsominor, so will be 'v', not 'V'. Here - Am.

But we need to be careful whether you're saying the mode is D Dorian or it's the Dorian of D. Difference.

• It seems to be the dorian of D. Now something interesting: I've read the other day that Bach when he wrote his WTC there he didn't know the terms *major" and "minor" and notated them in ionian and aeolian (or dorian) ... but I can't find the source again. I will ask a question. Commented Feb 12, 2020 at 14:44
• @AlbrechtHügli - if it is the dorian of D, then tonic is E, and key sig. is o.k. Making it E Dorian.
– Tim
Commented Feb 12, 2020 at 15:10
• So it is the dorian of D = E dorian (f# and c#) and seems to be notated in aeolian of G with an accidental of c#) Commented Feb 12, 2020 at 15:21
• Dorian is a minor key (with m3), so tonic is designated 'i'. Therefore here, Dm=i. The dominant chord in Dorian is alsominor, so will be 'v', not 'V'. Here - Am. If it has the signature of D (2 sharps) then the tonic = E, and A = IV, D=VII. Do you agree? Commented Feb 12, 2020 at 16:34
• @AlbrechtHügli - yes, that sounds better. If key sig. of 2# is correct, and it's Dorian, it'll be E Dorian (the Dorian of D), making E=i, A=IV and D=VII. Does my answer need some editing..? I'm happier with modal stuff showing parent key sig., but often it's not written out like that.
– Tim
Commented Feb 12, 2020 at 16:43

You can use them exactly how you would use them in a major or a minor key. Your starting point (degree 1) is going to be different and will be the tonic of your mode. Aside from that, the only things that change are the numerals' case and the application of diminished or augmentations marks where appropriate.

So, if you're doing 1, 2, 5, 1 in Lydian for example:

F Lydian: I, II, V, I Fmaj, Gmaj, Cmaj, Fmaj

All major chords because we are modifying the degrees to fit C Major (parent scale.)

So the progression in major would be your standard:

I, ii, V, I

And Lydian, using F as your starting point, as your degree 1:

I, II, V, I

Dorian, with D as the starting point:

i, ii, v, i

etc...

• Lydian (I,II,V,I) and Dorian (i,ii,v,i) would be the same with any start point.
– Tim
Commented Feb 12, 2020 at 12:49
• Of course. Yes, I was just relating it to the C major modes to keep it simple. Commented Feb 12, 2020 at 12:50

it is noted that the key signature is D major

If you mean the song by Simon and Garfunkel the signature of D major would be 2 sharps (F#,C#) and it must be in E-dorian, and the C# would be the major 6th of dorian. That means we have a major IV (A) like Richard says.

Most images (sheet music) I found are in minor (looking like aeolian) with an additional accidental (major 6th!) what indicates that this must be dorian.

You'll find searching by images two different versions in d, one has the signature of of C-major => d dorian, another 1 flat=> d-minor (aeolian)

The following version (s. image) must be identical with yours (additional accidental=C#)

This one is notated in E-aeolian - compared with yours - it has only 1 sharp in signature and an additional sharp (C#) as an accidental. So don't mind so much the mode as the final chord will be the tonic (and here obvious the 1st note too!)

So Em = i, D=VII, A=IV, G=III

The problem has been discussed already here in Dorian of G (G-dorian) but we miss the signature of 1 sharp so it looks like aeolian of C (a-aeolian) with additional F#:

Analysis of Scarborough Fair