To the average pop music fan, J. J. Cale is an enigma. Rock luminaries such as Eric Clapton and Lynyrd Skynyrd have made the Nashville-based singer-songwriter's music well-known, but Cale himself remains a man of mystery, flouting pop convention by avoiding publicity, limiting his tours and otherwise minimizing his contact with the public.

Even at The Cellar Door, where Cale tonight ends a sold-out engagement, he is pursuing a similar policy. No sportlights or other attention-getting devices for Mr. Cale, please; he's content to sit off in a barely-illuminated corner of the stage, talking to the audience only at the end of his hour-long sets, when it comes time to introduces his five-piece band.

Cale's guitar, though, is as eloquent as he is reticent. Most of the time, is plays in a simple, direct style that owes a lot to the blues - not the intense, hypercharged Chicago-style blues but the lazier, more relaxed country blues. His version of "Call Me the Breeze," for example, is far more easygoing than the Lynyrd Skynyrd hit.

The deadpan delivery with which Cale sings his laconic lyrics accentuates these qualities, as do the consistently understated rhythms his band favors. "After Midnight" and "Magnolia," which features a breezy mandolin solo, were so laid-back that one waiter at the club was moved to remark that "these guys are the epitome of mellow; they don't even break a sweat."

"Crazy Mama" and a blues medley that began with "Got My Mojo Working" were the only exception to this. Cale played a biting slide guitar on the former number, injecting a bit of unexpected spunk into the proceedings and showing that though a hupnotic blues groove is his favorite approach, even J.J. Cale occasionally feels a need to go uptempo.