So I'm trying to figure out how adding dominants to a chord progression works, i know how to harmonize a major scale

Ab Gbm Cm Db Eb Fm Gdim

how would adding dominants to this key work?
or is it based on the progression your using? like I IV V. or maybe something else entirely.

Also, if you're harmonizing a mode, lets say D mixolydian
D E Gb G A B C

will the harmonized D mixolydian scale look like
D Em Gbdim G Am Bm C
or
D Em Gbm G A Bm Cdim

I've been learning theory for only about 2 months so it's kind of hard to soak it all in
I'm not sure what you mean when you say adding dominants. The Eb is the dominant chord in Ab major.

If you mean secondary dominants, then basically you use the dominant for another chord in your chord progression (one that is not the tonic). So if you chord progression went A F#m E, then you could add a G#7 after the A, giving you A G#7 F#m E. In this case the G#7 is the secondary dominant, because it is the dominant of the F#m but F# is not the tonic, A is.

As for the mode thing, firstly in a scale no letter should apear twice. The formula for mixolydian is 1 2 3 4 5 6 b7, so if you apply that to the D major scale you get:

D E F# G A B C

To harmonize with this scale (simply put) you pick a starting note then take every other note. So for D you skip E, take F#, skip G and take A. Giving you D F# A which is D major. If you do this with every chord you get:

D Em F#dim G Am Bm C
Quote by Themann810
So I'm trying to figure out how adding dominants to a chord progression works, i know how to harmonize a major scale

Ab Gbm Cm Db Eb Fm Gdim

how would adding dominants to this key work?
or is it based on the progression your using? like I IV V. or maybe something else entirely.
You've harmonised the major scale in triads there - do you know how to work it out by stacking 3rds...so if you take C Major your first chord is C, plus a 3rd above C (E), plus a 3rd above that (G) - giving you C (Maj 3rd) E (min 3rd) G - which is C Major....?

If you do, then try adding another 3rd on top - which will give you 7th chords. When you get to the V chord you'll find you're adding a b7 on top of your major chord - which makes it R 3 5 b7, which is a Dom7 chord

Quote by Themann810
Also, if you're harmonizing a mode, lets say D mixolydian
D E Gb G A B C

will the harmonized D mixolydian scale look like
D Em Gbdim G Am Bm C
or
D Em Gbm G A Bm Cdim

I've been learning theory for only about 2 months so it's kind of hard to soak it all in
Its the same notes, and hence the same chords, as the relative major scale. Try working it out by starting with D Mixo and stacking 3rds. Then compare it to the relative major scale - G Major.

Remember diatonic scales use each letter once - so your D Mixo scale should be D E F# G A B C. So harmonised it will be D Em F#dim G Am Bm C
thanks
Are you thinking about the way in which blues and jazz artists just make every chord in a progression a dominant chord?
Call me Batman.
sort of, i noticed they do it quite often