UNLIKE so many other first-generation Southern rockers, Sleepy LaBeef has never stopped playing the mixture of boogie, blues and hillbilly that originally produced the rockabilly sound. Though LaBeef's legend has grown through the years, it has been his live performances, not his studio recordings that his fans speak of with missionary zeal. Now LaBeef has made a bone-rattling live album, "Nothin' But the Truth," that will turn skeptics into true believers, not just in LaBeef, but also in the uncompromised power of good old rock 'n' roll.

"Nothin' But the Truth" is more than a testament to LaBeef's 30 years of roadhouse rocking. Beyond his encyclopedic knowledge of Southern music and his faultless instincts as a singer and guitarist, the album reveals LaBeef as a performer who can still be seized by the moment and push a beer-soaked evening into rock 'n' roll heaven. The album seems to explode with energy as LaBeef and his band tear into Hank Ballard's "Tore Up Over You." LaBeef possesses one of those cavernous baritones that is perfectly suited to the swaggering braggadocio of Bo Diddley's "Gunslinger" or the ominous imagery of "Ring of Fire."

Though the pace of this live set is nearly frantic at times, LaBeef is so conversant with American roots styles that he effortlessly transforms hillbilly songs to blues and sets rock 'n' roll standards to a boogie beat. He makes it clear that these songs and styles are his language, one he obviously speaks best in front of a live audience. SLEEPY LABEEF --

"Nothin' But the Truth" (Rounder 3072). Appearing Friday and Saturday at the Twist and Shout Club in the Bethesda American Legion Hall.