Harmonic/Melodic Minor in Keys?

Question

How does one find the key to a scale like harmonic minor, or is out of key?

Answer 1

Harmonic minor is a variation on the more familiar natural minor scale. The only difference is that the 7th scale degree is raised by one semitone. This enables the use of a dominant V7 chord to create a greater sense of tension, to be released to the minor i chord. In natural minor, this would be a much more mellow effect.

Finding the key signature in harmonic minor would be similar to finding the key signature in natural minor. The best way to figure it out is to look for the tension and release of the piece. Once the song releases tension, it will do that on the i chord. Finding the root of that chord (for example, a resolution to a B minor chord has a root of B) would give you the key signature in most simple cases.