2

I often see roman numerals and figured bass together when labelling chords but are both really necessary? Surely the Figured bass will have accidentals if the chord is to be modified in some way so doesnt that make the chord label redundant?

armani
  • 9,033
  • 3
  • 23
  • 60

2 Answers2

4

The Roman numeral label describes the function of the chord; the figures describe the inversion or other modifications. Figures by themselves only describe which notes to play, and Roman numerals by themselves only describe the basic function of the chord. The two together give a more complete description of the specific way in which the notes of the chord are expected to behave within a piece of music.

See also: How to use figured bass over a stationary bass note

Aaron
  • 70,616
  • 10
  • 97
  • 243
  • Figures also show the function too dont they? The note in the bass and the figured bass symbols give you all you need to see whether it is ii or V or vii... Maybe the roman numerals make it easier but they are not necessary, what do you think? – armani Sep 10 '21 at 14:50
  • 1
    @armani None of it is strictly necessary, including the figures — you can just look at the notes. That's the point of both the Roman numeral and the figures: they allow analysis at a glance rather than having to study the score every time. – Aaron Sep 10 '21 at 16:15
  • Thanks Aaron. The difference between looking at the notes and looking at figured bass symbols or roman numerals is not equal to the difference between looking at roman numerals or figured bass. I was asking if the numerals become redundant with the figured bass somehow or are there times where the numerals are really necessary in definining what chord is in the score. – armani Sep 11 '21 at 08:11
  • @armani Suppose the notes in the score are C-E-G and the figure is 5-3. All you know is it's a root position chord. What is the harmonic function of that chord? That is, what Roman numeral would otherwise be assigned to that chord? – Aaron Sep 11 '21 at 13:16
  • Figured bass also requires a bassline with notated, fixed notes (e.g. C-G-C-G). Romans numerals don't and are actually key-agnostic (i.e. "I-V-I-V6" tells me nothing about which key the passage is in). – Dekkadeci Sep 11 '21 at 14:59
  • 1
    @Dekkadeci Roman numerals are supposed to be key agnostic. They describe the function of the chord within the harmonic context. – Aaron Sep 11 '21 at 17:07
  • Aaron you would have to look at the bass note.... isnt that the same as a roman numeral... If the key signature is one flat you know it is a V chord because C is V of F. But I get it... maybe it is just easier with the numeral. – armani Sep 11 '21 at 17:09
  • @armani What if the piece modulated at some point before the C-E-G? It would no longer be the V chord. – Aaron Sep 11 '21 at 17:12
  • @armani Come to think of it, I never said what key the piece was in in the first place. The chord could be IV in G, III in A minor, VI in E minor, V/V in Bb major, .... – Aaron Sep 11 '21 at 17:39
  • 1
    I understand what you mean. Thanks for explaining and I totally see the difference – armani Sep 12 '21 at 08:05
1

Figures are used with Roman numerals to show the inversion. In their original function as performance shorthand, the figures accompany a bass part, so they indicate which chord to play. For example, given a C bass note and a key signature of one sharp, a 6 means the chord is A minor while the absence of a figure means it's C major. If the key is G major, that's either ii6 or IV.

If you know any three of four quantities, you can determine the fourth:

  • bass note
  • Roman numeral
  • figure
  • key

The figures, in other words, aren't strictly necessary when you write a roman numeral analysis under a score, but the figures allow the analysis to stand alone. Without the figures, for example (or, more precisely, using only 7 to indicate 7th chords without regard to inversion), it wouldn't be clear that this is a harmonization of an ascending scale:

I V4/3 I6 ii6/5 V IV6 V6/5 I

phoog
  • 16,807
  • 2
  • 33
  • 61