The Byzantine, also referred to as the double harmonic scale, has a formula of R-b2-3-4-5-b6-7 and makes for ... the chords of G major, F# augmented, D# diminished and C minor.

There are other scales ... harmonic minor has a unique sound to it, which makes it rather appealing to the ears. The reason for this is that it features a major 7th interval (1-2-b3-4-5-b6-7 ...

Harmonic minor keys are used when writing chords. There is another version of the minor key known as the melodic minor. This is used when writing a melody. Each key signature has two possible keys.