The harmonic minor scale differs from the natural minor scale in that it has a raised 7th note. This gives it a kind of Eastern or Arabic sound. The step pattern is therefore:
So, in the key of A, we get:
On the guitar, we could play it on the G string (3rd string) like this:
Since it is not entirely functional to play a scale on a single string, we can find the notes of this scale across all strings, as follows:
This pattern can be used when the root note of the natural minor scale falls anywhere on the 5th string.
This pattern can be used when the root note of the natural minor scale falls anywhere on the 6th string.