I find it easier to listen to the 3 scales below on a keyboard.
If you listen to Cmajor, Relative A harmonic minor and Relative A melodic minor.
You start to hear some sounds drawing closer to one sound, and some sounds sound like they are being stetched away from one sound.
This is where you start hearing tension and relaxation.
Lots of improvisation plays on these tricks to give different feelings to their music.
If you listen to the melodic minor when it goes up and down,
it seems to rise and fall naturally even though it plays a different note coming down, if you played coming down with the same note going up, it just doesn’t sound right.
Whereas with harmonic minor, keep the same notes up and down sounds ok.
I’m into crawling with improvisation, and would also be interested to the answer to Michael’s question.