The Spanic Boys are roots rock's amusing answer to the Judds--they're a crack rockabilly foursome fronted by a father-son pair named Tom and Ian Spanic. Neither of the two are what you'd call svelte, and sometimes from the back of the club they look like a pair of bespectacled hillocks with Telecasters. The kicker is that they play those Telecasters just fine, thank you, and Spanic fils is comfortable beyond his years in the tarted-up C and W idiom he wanders in. "Keep on Walking" (I'm working off their self-titled Rounder album) has a timeless lilt and a mahogany sheen to the harmonies; the dirty guitar-strewn "Undercover" heads off into Georgia Satellites territory (almost Faces territory!) and comes back alive and healthy. They're a blast live. Tonight, FitzGerald's, 6615 Roosevelt, Berwyn; 708-788-2118. Saturday, Schubas, 3159 N. Southport; 525-2508.