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?
2 Answers
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
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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?– user35708Commented Sep 10, 2021 at 14:50
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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.– AaronCommented Sep 10, 2021 at 16:15
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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.– user35708Commented Sep 11, 2021 at 8:11
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1@Dekkadeci Roman numerals are supposed to be key agnostic. They describe the function of the chord within the harmonic context.– AaronCommented Sep 11, 2021 at 17:07
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1I understand what you mean. Thanks for explaining and I totally see the difference– user35708Commented Sep 12, 2021 at 8:05
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
