With each passing spring, the four-day music fest in Florence known as Country Thunder gets a little less country and packs a little less thunder. For example, two years ago, John Fogerty headlined one night in the converted alfalfa field and fired up some old chooglin' Credence Clearwater Revival hits. While Fogerty is obviously a country music fan and has seriously dabbled in the genre with his two Blue Ridge Mountain Rangers records, he is not synonymous with country music. It may have been a stretch to put Fogerty on a Country Thunder bill, but that's nothing compared with this year's Saturday headliner, Kid Rock, who despite scoring two Top 40 country hits with "Picture" and the Skynyrd/Zevon mash-up "All Summer Long," is known more for his rowdy hard-rock rappin' than for his twangy shitkickin'. That said, Rock is still more interesting than Country Thunder's other 2010 headliners, Miranda Lambert and Keith Urban. At least Kid brings a hard-drinkin', hard-livin' Hank Williams-style attitude to the proceedings. As for the rest of the event, amidst the smattering of country-pop acts, up-and-coming hitmakers, and the obligatory filler of singers who haven't come within tobacco-spitting distance of relevance in the past few years, there is one true legend and one bona fide oddity on the bill. Country deity Willie Nelson incomprehensibly plays the slot right before Kid Rock on Saturday — the 76-year-old must need to hit the hay early these days. Kevin Costner and Modern West, who most assuredly got the sweet gig because their lead singer was the dude in Dances with Wolves and Bull Durham, play the slot before frosted-tip pretty boy Urban on Friday. While the music may not be top-notch country at the 2010 fest, it should be worth the price of admission on Saturday to see how the younger contemporary country audience reacts to Willie Nelson ("Whoa, that dude is old . . .") and to see if any the older 'necks in attendance get their beer guts bouncing during Rock's set.