The 9 overdraw is a semi-tone above the 9 blow and a minor third above the 9 draw. It second position it would be a flat second, which could be used in gypsy or eastern music.
How to do it
Similar to the 7 overdraw (seems a bit easier to initiate than the 7 to me), being a higher note it’s more towards the tip of the tongue with smaller mouth volume, this time think about doing the 10 blow bend but drawing instead.
