Neapolitan Major is your friend.

The Neapolitan Major scale is sorely misunderstood nowadays, and I am hoping to change that. One of the best ways of using it is while the Melodic minor is being played. Raise the root of the Melodic scale, that makes Alt bb3 (mode VII of Neapolitan Major) and revel in its sound, then lower the note and modulate back.

For the more daring musician, follow the procedure above then raise the second note in the Neapolitan Major scale to arrive at a new Melodic scale. The Neapolitan Major scale is unique in the fact that its intervals are one step away from not one Melodic scale, but two!

To untwist yourself from its grip, lower the sixth degree to make Neapolitan minor and then raise the second to make Harmonic minor, and voila, you are back in the normal world once more.