Hungarian gypsy scale
The Hungarian scale or Hungarian Gypsy Scale is a name given by different authorities to two different scale forms. The more commonly used of these scales can be found by sharpening the 4th degree of the harmonic minor scale to introduce an additional gap, or augmented second. This is a symmetrical scale that is very common in Flamenco. It is also used in both Carnatic and Hindustani music, in addition to showing up occasionally in Western Classical music selections, such as mm. 5-6 of Liszt's Sonata in B Minor. The scale is often used in the 5th mode, in which case it is referred to as the double harmonic scale.
The alternative (and less common) version is the asymmetric Aeolian #4 scale, the only difference being that the 7th degree of the scale is not raised. This form of the scale can also be used in the 5th mode and would then be referred to as the Neapolitan scale.
Other modern examples of these scales in use are Foreigner's "Blue Morning Blue Day" where both forms of the scale are used (the lowered 7th only occurring at the very end), and even more recently, Arctic Monkeys'[page needed] "Brianstorm," where both forms of the scale are also being used, interchangeably.
Scale in corresponding keys 
A Hungarian Gypsy:
A B C D# E F G/G#
C Hungarian Gypsy:
C D Eb F# G Ab Bb/B
E Hungarian Gypsy:
E F# G A# B C D/D#
The structure of this scale is (w = whole-step, h = half-step, + = augmented):
w - h - + - h - h - w/+
2 1 3 1 1 2/3
- http://jguitar.com/scale/C%23/Hungarian%20Gypsy - Illustration of the scale on a guitar of Double Harmonic variety.
- http://www.power-chord.com/gaff/mapper/ - Illustration of the scale on a guitar of Aeolian #4 as Hungarian Gypsy.
Further reading 
- Hewitt, Michael. 2013. Musical Scales of the World. The Note Tree. ISBN 978-0957547001.