signed to RCA for some $30 million is due to a showbiz savvy that would please Elvis Presley's carnival-bred manager, Colonel Tom Parker, and to an abiding passion for the kind of rude rumble that a Texas bluesman like Lightnin' Hopkins would produce when he plugged in his electric guitar.

"I got down with a fuzz box," sings Billy Gibbons on "Fuzzbox Voodoo," a sinewy number from Antenna, the group's new album, that's about more than the guitarist's favorite distortion device. The fuzz box and other such gadgets have certainly helped Gibbons sustain his tradition-bound trio, but it's that rarest of rock-band attributes, a sense of humor, that has been the group's true saving grace. For while ZZ Top owe their latter-day success to a cheesy video image based on cool cars, leggy babes and big beards (except, of course, on the cleanshaven chin of drummer Frank Beard), you can always see the band winking from behind their cheap sunglasses.

In fact, ZZ Top have always hitched their guitar riffs to songs about cars and girls. The group's first big hit, "La Grange" (1973), celebrated a Lone Star brothel, with the lascivious glee of Gibbons' vocal underscored by a whiplash guitar that still sounds fresh. Their next album spawned another group-defining standard, an up-tempo boogie that established a vocal niche for bassist Dusty Hill: "Tush."

Both songs were spiced by the sexual innuendoes common to the blues and nailed by the soulful wallop of Gibbons' rhythm guitar, a musical characteristic that distinguished ZZ Top from their hard-rock contemporaries. The group can be faulted for toeing a stylistically conservative line; the result, though, has been a remarkable consistency born of the notion that successive albums needn't so much present a new statement as a novel twist on what has come before.

The group had the goofy gall to admit this approach by titling its 1990 album Recycler. Yet recycling is also part of the blues tradition, as artists frequently grafted new lyrics onto familiar musical frameworks. Elmore James even went so far as to re-record his biggest hit, "Dust My Broom," and call it "Dust My Blues." So it's only logical that when Gibbons takes a slide-guitar solo on Antenna's "Girl in a T-Shirt," he rips into the triplet rhythm that James himself lifted from the Delta blues.

The drawback of such a limited approach is that a ZZ Top album is ty