Figured Bass - Help needed!

[bluesparky]

Hi all,

I've been re-visiting a few things I've learned over the years and I've become a little unstuck over a couple of things with Figured Bass.

I seem to have contradicting notes with regards to doubling up of notes from 3 note chords to 4 note chords.

From what I've been able to de-cipher from my mish-mash of my notes, these are the rules (as far as I can see).
Would anyone agree with this?

5/3 - Double the root (or sometimes the 5th)
6/5 - Double ANY note
4/3 - Double the 5th
6/3 - Double ANY note

6/3 - If the interval between 6 & 3 is:
PERFECT 4th - Double any note EXCEPT the bass
AUG 4th - Double the BASS

6/4 - ALWAYS double the bass note


DOUBLE THE ROOT FOR:
Any 5/3 chord
Any 6/3 chord except for Diminished chords (ii or vii)
NEVER in 6/4

DOUBLE THE THIRD FOR:
Any 6/3 chord (except if it's the leading note)
NEVER in 6/4 chords
NEVER in a 5/3 unless:
it's minor OR
Maj 3rd in a minor key & part of a V - VI progression

DOUBLE THE FIFTH FOR
Any 5/3
Any 6/3 except for Diminished chords (ii or vii)
ALWAYS 6/4




Another list of rules I've found in my notes include:
Root position – 1 or 5
First Inversion – anything goes
Second inversion – 5
Watch out for:
• • diminished chords (ii° and vii°) – ONLY double the third
• • chord VI in minor keys CAN double the third
• • Vb – CAN’T double the third


As you can see, it's a bit all over the place and I'm wondering whether all of the above facts are true, or whether a couple are incorrect or whether I'm missing anything.


Thank you for any help or pointers.

Cheers,

Mark

[Gazza 2905]

Whoosh....straight over my head!