Originally Posted by hauk
I like that one, except with the C raised a half step to a C#. It adds a little tension, a more exotic quality in my opinion. And that is the only Middle Eastern scale I know.
The sequence of notes for Hijaz from the tonic is
half – augmented – half – whole – half – whole – whole
The tension of the Hijaz scale exists between the augmented second and diminished third degree. The four through seventh degrees provide the resolution. If you augment the seventh degree, it would tend to conflict with the tonic when beginning the scale again, because you would have two augmented/half-step intervals of tension competing with each other. Try doing this up the keyboard and listen.
If you raise the seventh degree a half-step, you would have an augmented seventh and no longer have a Hijaz scale (also called a Phrygian dominant). If you showed up at a Jewish or Arabic jam session and raised the seventh degree of the scale like that, regardless of key, you wouldn't fit in.