Surprisingly durable and devoted, rockabilly is a vigorous American subculture, much like the Elvis-ites. The slicked-back pompadours, tattered sleeveless oxfords, tattoos and souped-up cars at rockabilly shows make it hard to tell whether you're in a dusty Stray Cats video or cavorting with Eddie Cochran's first fans. Kim Nekroman, a submarine operator in the Royal Danish Navy, caught the bug in 1989 and left the service to form the Nekromantix. Melding a punk energy and kitschy pop-culture patois with the already rambunctious rockabilly sound, the three-piece followed the lead of psychobilly progenitors The Cramps. They remained a Danish phenomenon until three years ago, when they had their first American release, Return of the Living Dead, on Epitaph. Nekroman has a deep croon, and avoids the theatrical weirdness of, say, Lux Interior. Playing a stand-up bass shaped like a coffin, he's joined by Peter Sandorff, whose classic Gibson wails and rolls through classic reverb guitar lines. After 15 years, they're remarkably tight, and last year's Dead Girls Don't Cry featured an even better batch of songs. So while rockabilly hasn't changed, it appears the Nekromantix are just getting better.