A dominant seventh flat ninth chord is composed using a root/1st, major 3rd, perfect 5th, minor 7th and minor 9th (or R/1-3-5-♭7-♭9) intervals played simultaneously. Generally written as C7(♭9), C7(-9) or C(-7-9), it is good practice to simply use an uppercase C followed by a super scripted 7(♭9) to represent it in writing (ie: C7(♭9)).
Dominant seventh flat ninth chord profile
|Intervals||root/1st, major 3rd, perfect 5th, minor 7th, minor 9th or R/1-3-5-♭7-♭9|
|Stability||Dissonant, unstable, unresolved|
|Common names (examples in C)||C7(♭9), C7(-9), C(-7-9)|
|C Dominant seventh flat ninth chord voicing #2|