SLEEPY LABEEF 100% GRADE A HONKY-TONK

Rockabilly giant Sleepy LaBeef stands 6 feet 6 inches tall and weighs ''between 265 and 292,'' he says, ''depending on how hungry I've been.'' His concerts are as grand as his measurements. With his basso profundo booming over a boogie- woogie beat, LaBeef creates stream-of-consciousness medleys of songs by such dissimilar artists as George Jones, Little Richard, Muddy Waters, and Nancy Sinatra. Born Thomas LaBeff in Smackover, Ark., the 56-year-old musician got his nickname on his first day at school ''because I look like I'm about half asleep,'' he says. He dropped out in the eighth grade, traded his hunting rifle for a guitar, and by 1954 was opening for Elvis Presley. Except for playing a swamp monster in 1968's The Exotic Ones (''typecasting,'' LaBeef jokes), he has been touring ever since, appearing ''everywhere from Texas honky-tonks to Spanish bullfighting arenas.'' And with his massive stage presence, no one ever has to ask, ''Where's LaBeef?''