I just had a major breakthrough

[HeartSoulandSpirit]

Hello All,

Wow, call me crazy, but for a long while I was thinking that a "9th" and "add9" were the same thing.  So, when I would play...lets say C,D,E,G
I was always thinking that was a C9....not a Cadd9.  I now know that a C9 is  C,D,E,G,Bb becuase a C7 add9.

Now, and most importantly, when/how is a 9th (C9) used?  Would it be used like a 7th (usually on the 5th tone,  I - IV - V9- I) just to make it sound more full?

The add9 just makes a chord sound more....beautiful, or plush.  Now what about that 9th?

Anyway, just had a small revealation and thought I would share and get some more insight.  Be Blessed LGM

[T-Block]

The C9 (or any dom. 9th chord) is used as a substitute for any dominant or secondary dominant chord. Examples:

2-5-1 progression, key Bb

C / E-G-Bb-D (C9) *secondary dominant to 5
F / Eb-G-Bb
Bb / D-F-Bb


5-1-4 progression, key C

G / F-Bb-D
C / E-Bb-D (C9) *secondary dominant to 4
F / E-A-C