A most angst-ridden Christmas

The ho-ho-horror.... The ho-ho-horror....

Well, what do you expect when you celebrate the Christmas season with Nine Inch Nails and Korn?

Those bands and to a lesser extent System of a Down brought a sack full of angst to the first night of the 16th annual KROQ Almost Acoustic Christmas concerts at Gibson Amphitheatre on Saturday.

NIN's Trent Reznor and Korn's Jonathan Davis are two of the most cathartic performers in rock, upchucking a lifetime of inner torment and forming it into music of overwhelming force. Even though both have turned to slightly more conventional approaches on their latest albums, onstage there was no compromise in their enraged exorcisms of betrayal, hypocrisy and abuse.

Korn marked the evening's turn from warm-up time to major event, returning from a period of transition in which it changed record companies, lost guitarist Brian "Head" Welch (to the Lord, of all things) and collaborated with the pop-stained writing-production team the Matrix for its new album, "See You on the Other Side."

None of that seemed to affect the Bakersfield-bred band's performance Saturday, as it took the stage to the most avid welcome of the evening. With its menacing biker look, outlaw charisma and us-against-the-world attitude, Korn is the Oakland Raiders of rock, a team that's in the league yet somehow apart from it.

Korn didn't suffer any loss of depth or power playing as a four-piece, mounting a rich, loamy sound whose textures had no trace of harshness. It was like a massive, weighty cloud of anger and anguish.

Davis' gnarled vocals sometimes turned into a guttural chatter, but he also flashed a bit of crooning at the end of the new "Liar." The audience seemed to receive this gentler side of Korn with no trace of anti-pop hostility.

Nine Inch Nails has been another comeback story this year, with Reznor going sober and reclaiming his position as rock's poster boy of pain. His retooled band elevates rock guitar and demotes electronics and keyboards, suiting the more hook-focused nature of the songs on the "With Teeth" album.

Reznor and company have already made their statement in Southern California this year, with memorable appearances at Coachella and the Hollywood Bowl, so the Acoustic Christmas spot was more in the way of summation. But the band played a take-no-prisoners set, an unrelenting hour-plus powered by percussive, staccato guitar-thrashing from Reznor and Aaron North and punctuated by much hurling of instruments.