10 p.m., Miller Lite Stage 
(Riverfest Amphitheatre).

Bill O’Reilly’s once-sworn enemy and actor in 2004’s Academy Award-winning Best Picture “Crash” also happens to be one of the most consistently entertaining rappers out there. After 10 years of hit after hit — his singles discography might as well be called a collection of the best ass-shakers of the decade — the instantly recognizable timbre of his voice has practically become an immediate seal of quality. It would be hard to find another rapper that has more fun nailing syllables on the beat. Luda’s flow? It’s kind of untouchable when he’s hitting the gas, then the brakes, doing verbal gymnastics the entire time. Do you remember how you went “ohh!” (and you did because everyone did) when you first heard his guest spot in Chingy’s “Holidae In?” “Some call me Ludacris, some call me Mr. Wiggles/far from little/make your mammary glands wiggle?” Those are words from a cat who can tell you tons about stressed and unstressed syllables. You can’t even read that without feeling cool. He’s hilarious, he’s awesome, he’s an immediate party-starter and he’s probably the most anticipated act for Riverfest this year.