Alot of the 50's Rockabilly guys grew up listening to jazz and swing players, and the solo to Rock Around the Clock was actually played by a session player that was a jazzer, (his name escapes me, Sal Somebody?) one of the things I've noticed about most rockabilly playing is no matter what scale is being used, somewhere in their playing, chromatics always seem to make an appearence somewhere, could be in the solo or in the bassline, they seem to be a regular staple of the style, which is why I always thought Brian Setzer really did justice to Rockabilly when the Straycats came out, the boy had the right riffs, guitar, amp and even the right hair, a great rockabilly album if you haven't heard it before is Jeff Beck and the Big Town Playboys' Crazy Legs. Rockabilly was 50's Shred and I think really an overlooked part of the legacy of Rock music, those guys really were pioneers in so many ways........................