How to form a 7th Chord with flat 5th (such as C7-5)
A seventh chord with a flat 5th is simply what it says — a dominant 7th chord with the 5th scale note lowered 1/2 step. The symbol for a C7 with a flat 5th would be C7-5. The symbol for an F7 chord with a flat 5th would be F7-5.