# Figured bass for a Dom 7th chord



## rbarata

Hello, my friends

Maybe I'm confused but for a Dom 7th chord the formula is 1-3-5-b7.
So, I think the figured bass (showing all the nºs) should be 7-5-3 with a natural sign before the 7 (in this case I'm using the nat sign because I'm thinking about the A7 in the key of A Maj. If I was in C Maj then it should be a b (flat) before the 7.

Am I thinking right?

I don't know why all the examples I've found for this put only a 7 without any sign.


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## EdwardBast

In the key of A major, if you have A in the bass and the figure "7," the note indicated by the figure will be G# and the chord will be a major 7th chord, not a dominant 7th. If you want a dominant 7th chord on A in the key of A, there will be a natural sign in front of the 7 and the chord will be V7 of IV, a secondary dominant.

Now if what you want is the V7 chord of A major in root position, that would have E in the bass and the figure "7," since the 7th would be D natural and D is already natural in the key signature — 7 without an accidental sign always indicates a diatonic 7th, that is, the one that occurs naturally in the key.

For root position triads one never needs to use 3 and 5 in the figures (unless they are altered), these are assumed.


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## rbarata

Thank you for the reply, Edward.

So, I'm thinking correctly...any accidental out of the key implies an accidental, whatever it would be.
I was puzzled because I couldn't find any figured bass notation with the accidental...probably because all the examples were of a V chord and not I as asked.



> ...and the chord will be V7 of IV, a secondary dominant.


So, when notating chord functions, whenever a secondary dominant function applies it must be always shown or there are exceptions?


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## rbarata

Considering the above I am thinking why the natural sign on the G?


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## EdwardBast

rbarata said:


> Considering the above I am thinking why the natural sign on the G?
> 
> View attachment 109625


It's just cancelling the G# on the first beat. The last six chords in that progression can be analyzed in E minor. In fact, the chord you have circled has no viable Roman numeral designation in C major and really must be analyzed as the Vii°7/V in E minor.


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## EdwardBast

rbarata said:


> Thank you for the reply, Edward.
> 
> So, I'm thinking correctly...any accidental out of the key implies an accidental, whatever it would be.
> I was puzzled because I couldn't find any figured bass notation with the accidental...probably because all the examples were of a V chord and not I as asked.
> 
> So, when notating chord functions, whenever a secondary dominant function applies it must be always shown or there are exceptions?


If one is doing typical Roman numeral analysis, yes, one should indicate the nature and function of any chords out of key.


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## rbarata

> It's just cancelling the G# on the first beat.


Opss...haven't noticed that one. Now it's clear...



> In fact, the chord you have circled has no viable Roman numeral designation in C major and really must be analyzed as the Vii°7/V in E minor.


It might be hard to explain but, if possible, could you explain how the Vii°7/V fits in E minor. I understand where the Vii°7/V came from but why E minor? Unless you're using the context (the final chord and others) the Vii°7/V could be something completely different.


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## EdwardBast

There's not really much to explain. The Vii°7/V is just a standard secondary dominant function chord preceding the dominant. (Note that in this case the I6/4 chord is just the dominant with an as yet unresolved 6/4 suspension.) It's commonplace. The chords preceding that are also in E minor: Vii6/5 of IV, IV.

The voice-leading in the last two chords is questionable. The G, a suspension, should have resolved down to F#.


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## EdwardBast

I meant in the last three chords. Both the 6 and 4, G and E respectively, should have resolved down.


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