7 p.m., Alltel Arena. $23.25-$38.25.The 10-day parade of nu-metal survivors (Saliva, Drowning Pool, Powerman 5000) culminates with arguably the genre's most popular group. Since 1994, the Bakersfield-based act has released a steady stream of angsty rap-infused metal. Now middle-aged, band members seem to be struggling to maintain their edge. Two years ago, they collaborated with the Matrix, the songwriting trio behind many of teen-pop's biggest hits. Earlier this summer, in an effort to reassert their position atop nu-metal's heap, they put out “Untitled,” an album that debuted at No. 2 on the Billboard charts despite mostly mediocre reviews (“warmed over Nine Inch Nails” among them). Still, chances are Korn hasn't mellowed onstage. (Lest you think otherwise, they've named their tour “Bitch! We have a problem.”) Look for a lot of teens in black shirts. Newer genre adherents Hellyeah, Five Finger Death Punch and Droid open the show.