Our penultimate chord type is based on a min7b5 chord, also known as a locrian chord. The difference here is that the melodic minor version of this chord contains a natural 9 and is the 6th chord of melodic minor.
Since the chord would normally take a locrian scale, we simply play a locrian mode and sharpen the 9th (2nd) interval. This gives us the characteristic melodic minor sound.
The chord symbol would be written from G as Gmin7b5nat9.
The scale will also work in a modal context over any min7b5 chord. You decide whether to play the natural 9 or the sharpened 9.
Here's the chart!
|Min7b5nat9||Locrian natural 9|
|Min7b5||Locrian/Locrian natural 9|