The Byzantine, also referred to as the double harmonic scale, has a formula of R-b2-3-4-5-b6-7 and makes for an interesting alternative to the major scale when soloing over major 7th chords.

You can apply this formula to any other triad or chord, always adding the 7th a tone below the root note. When you speak to jazz, blues, rock or pop musicians, and ask for a chord of C7 ...