theory from Frank Singer.comRoman Numeral Analysis | print this page | close this window |


Roman Numeral Analysis uses the scale-degree location of the root of a chord to describe its position, and in doing so also describes the chords function. In more complex harmonic situations, the diatonic scale (Ionian mode) is used to define the diatonic posts. These will serve as harmonic targets for non-diatonic passing and approach chords.

Diatonic Posts - examples in C
SCALE DEGREE 1 2 3 4 5 6 7
ROMAN NUMERAL
DIATONIC CHORD
I
Imaj7
IIm
IImin7
IIIm
IIImin7
IV
IVmaj7
V
V7
VIm
VImin7
VIIo
VIIm7b5
KEY of C C
Cmaj7
Dm
Dmin7
Em
Emin7
F
Fmaj7
G
G7
Am
Amin7
Bo
Bm7b5

Non-diatonic chords fall into a number of categories.
Modal Interchange can occur with chords based on the following scale degrees:

Available Modal Interchange Chords
scale degree 1 b2 2 b3 3 4 #4 / b5 5 b6 6 b7 7
roman numeral I bII II bIII III IV #IV / bV V bVI VI bVII VII
available quality maj7
min7
7
m7b5
maj7



min7
7
m7b5
maj7
min7
7

min7

m7b5
maj7
min7
7



m7b5
/ maj7


maj7
min7
7
m7b5
maj7

7

min7

m7b5
maj7
min7
7

min7

m7b5

Secondary Dominants resolve through the cycle of fifths to a diatonic target.

Secondary Dominants - examples in C
A7Dm B7Em C7F D7G E7Am
V7/IIIIm V7/IIIIIIm V7/IVIV V7/VV V7/VIVIm

Substitute Dominants [Sub V7] [Tritone Substitution] resolve down by half-step to a diatonic target.

Substitute Dominants - examples in C
Db7C Eb7Dm F7Em Gb7F Ab7G Bb7Am
subV7/II subV7/IIIIm subV7/IIIIIIm subV7/IVIV subV7/VV subV7/VIVIm

Passing and Approach diminished chords move between or toward diatonic posts by half-step root motion. This root motion can be hidden in the way the chord symbol is written, or hidden as an internal voice. There is always a chromatic connection with a diminished seventh chord and its target.

Ascending Diminished Seventh Chords - examples in C
Cmaj7 C#o7 Dmin7 D#o7 Em7 Eo7
[app. only]
Fmaj7 F#o7 G7 G#o7 Amin7 A#o7 G/B Bo7
[app. only]
Cmaj7
Imaj7 #Io7 IImin7 #IIo7 IIIm7
also C/E
I/3rd
IIIo7 IVmaj7 #IVo7 V7
also C/G
I/5th
#Vo7 VImin7 #VIo7 V/3rd VIIo7 Imaj7

Descending Diminished Seventh Chords - examples in C
Cmaj7 Co7
[app. only]
G/B Bbo7 Amin7 Abo7 G7 Gbo7 Fmaj7 Fo7
[app. only]
Em7 Ebo7 Dmin7 Dbo7 Cmaj7
Imaj7 Io7 V/3rd bVIIo7 VImin7 bVIo7 V7
also C/G
I/5th
bVo7 IVmaj7 IVo7 IIIm7
also C/E
I/3rd
bIIIo7 IImin7 bIIo7 Imaj7

©2003, Frank Singer | Naked Kitty Productions | chelaBOP | Frank Singer.com
All Rights Reserved