No not G
Why?
Because the C chord in Db is usually a half diminished chord
remember there is no G in the Db scale the g is flatted to the F#
are you with me so the dominant of C half diminished is the Gb
so your shell voicing in your left hand could be C, F# and Bb against either an A triad or a C triad or a F# triad or a Eb triad
Now if you usually play your 7-3-6-2-5-1- progressions with the 7 as a regular minor chord without the flat 5 or you play it as a dominant chord then by all means Use a regular 5 and build your related diminished on that so
in our example if you were to play the C chord as a major or regular minor with a G natural in the chord then you would use G as the dominant and build the diminihsed on the B
I usully play my C chord as a half diminished so i would build my diminihsed chord on the third of F#
Remember it is all about the chord you are using look at F
the third scale tone of Db
I usually play that as an Augmented with a raised 5 f ,A ,C#, Eb,
so I would use the third of Db which is F and I would use the triads D,g.Bb Db
I know this sounds confusing but once you begin to do a chord or two it starts to make sense and you will even find some voicings you already use
for example the Ab tirad over the Bb we all use that one as a sus chord
or the Btriad over the Db shell we use that as a Seventh chod as we head to the F#
This is how I would use the 7-3-6
Using the notes of the A diminished chord
ist the Eb triad
C, Bb/ Eb G Bb F, A/ Eb, F3, A, C Bb Ab/ F, Ab, B, Db
The F# triad
C, Bb/ F#, Bb, Db, -- F, A, / Eb. A. Db ---- Bb Ab/ F, Ab, C, Eb
The A triad
C, Bb/ A, Db, E, F, A,/ A, C, Eb,, Bb, Ab, ? Ab, C, Db, F
C, Bb,/ C, E, G, -- F, A,/ C. Eb, F#, Bb, Ab/ Db, F, Ab
I hope this clears it up
if I used g as my Dominant You would use the triads built on the Bb diminsished
They sound nice too one that sounds good is the Etriad
C,Bb/ E, G#, B F, A,/ Eb, F#, A, C, Bb, F, C/ Eb, Ab, Db,
So you could use the G as your dominant on the C l
Thanks for digging into these
I appreciate your taking the time with my humble contribution
God Bless