The Spanish Scale or the Spanish Gypsy Scale as it is also known is one of the most intresting and to my ears, one of my favourite sounding scales. It is known as the Dominant Phrygian Scale. It is more or less a normal Phrygian mode with a sharpened 3rd note. Therefore it is then the 5th mode of the Harmonic Minor Scale.
The Intervals are:
1 b2 3 4 5 b6 b7 or in half steps the intervals are then - 1-3-1-2-1-2-2.
So a common C Spanish Gypsy Scale would have the following notes:
C, C#, E, F, G, Ab, Bb.
This scale is used all over Spanish music but also within alot of tasty western music too, whether they know they are using it or not, it is used because of the nice feel and flow about it. Rock music has alot of these influences in it. Especially bands like Metallica and guitarists like Steve Vai. It has that neo-classical feel to it, but like anything it dosen't have any limits as to where you can go with it.
The corresponding Spanish Scale from the C scale would be the E Spanish. But remember because it is harmonic mode it you must raise the G note to a G#. So the notes in the E spanish scale would be:
E, F, G#, A, B, C, D.
So in the key of C the relative Phrygian Scale is E Phrygian. Giving us there notes:
E, F, G, A, B, C, D.
Playing the Dominant Phrygian scale over an Emin Chord would then clash when the G# note is played. This is because it clases with minor 3rd G note in the chord. So it is common for musicians to change the Emin into an E Major chord instead. The E major chord contains the G# note that is found in the Spanish Scale helping it give that sound.
A common two chord progression to get going with is Emin to Amin. Using the E phrygian scale over this would be perfect. But if you changed the progression to Emaj to Amin the Spanish Scale is then perfect and comes into its own simply because of the reasons we talked about above.