Harmonic minor is very close to a mode, Aeolian, also known as natural minor, but to change it you have to start with Aeolian and raise 7. You can also start with Ionian, major, and lower 3 and 6. But no matter how you get there, you don’t end up with the notes that match a major scale, so harmonic minor is not a pure mode but an altered mode, also called an artificial scale. Here is one of the most famous pieces in the world using this scale.
Jazz players also name this scale “Phrygian dominant” if something revolves mostly around the 5ths degree of the scale. Hava Nagila fits this description most of the way through, since it only convincingly moves to degree 1 of the harmonic minor at the very end.
This gets into a thorny problem. Can you have modes coming from scales that are not modes to begin with? Aren’t these “altered modes”?
I understand the thinking but don’t like. It makes things horribly complicated. Jazz player are simply thinking of the harmonic minor scale, from 5 t0 5 (meaning from degree 5 to degree 5), which does this:
G A Bb C D Eb F G is G harmonic minor.
The scale being talked about is:
D Eb F# G A Bb C D, with only F# different. I have have to, I prefer to look at it another way, as an altered major or Ionian:
D E F# G A B C# D. D major
D Eb F# G A Bb C D, b2 b6 b7, with jazz players saying b9 and b13.
This is also D Mixolydian: D E F# G A B C D, because Mixolydian already uses b7.
D Eb F# G A Bb C# D is Mixolydian with b2 and b6.
But this seems like a lot of trouble when it is just Harmonic minor, starting on 5.