Harmonic minor came about because 'some' classical musicians couldnt stand the fact that the stock standard minor scale didnt resolve with a semitone preceding the root.
The scale is generally used over Minor(maj7) chords, but it can also sound hip if you state some harmonic minor ideas over regular minor tonality. Just dont over use it in that situation, its more of a colouring device.
A good way of memorising the harmonic minor modes is by thinking of harmonic minor as an aeolian mode with a sharp 7. Then use that method for the other modes within the scale. So for example, all the modes would be
1st: Aeolian(Maj 7)
2nd: Locrian(Maj 6)
3rd: Ionian(Sharp 5)
4th: Dorian(Sharp 4)
5th: Phrygian(Maj 3) - also known as phrygian dominant
6th: Lydian(Sharp 2)
7th: Mixolydian(Sharp 1) - used over diminished chords
They've got official names, but my brain is fried from drinking too much last night so i cant remember them. I find the above method alot easier to remember though, because all you have to do is think of the regular modes with one sharpened note.
The most commonly used modes out of the scale are the ones starting on the 5th and 7th degrees.
The 5th mode(phrygian dominant) can be used over dominant chords that resolves to a minor chord.
egs: G7 | Cmin7
...........unless stated otherwise, like: G7(#9) | Cmin7 <-u wouldnt use it in that situation.
The actual chord symbol that goes with this scale would be: G7(b9, b13) | Cmin7
The 7th mode can be used over diminished chords
The 3rd mode is also a good one to use over Augmented chords(or Augmented Major7 chords), but steer clear of the natural 4.
Hope that helps. Check out "Caravan". The C7 vamp is based around a C phrygian dominant sound(F harmonic Minor). You might find some nice groove ideas by checking out some of those recordings
