For the music industry, the Christmas season has always had one purpose: to push "oldies but goodies" acts through one way or another, whether it's "Best Of" box sets or massive stadium tours by artists at least 15 years past their expiration date. Thus, it's no surprise that Culture Club, Barry White and Blondie are making the rounds this season. But it's shocking, to say the least, that Nine Inch Nails [ tickets ]' Trent Reznor, one of the most groundbreaking rock acts to emerge this decade, should purposefully thrust himself into this category.

Although ''The Fragile,'' the band's first album since '94, went to the top of the Billboard charts the first week it was released this year, an older and less self-assured Trent Reznor used only a sprinkling of new material during the sold-out London show, his second in years. Out of the 22 songs in the two-hour show, only nine were ''Fragile'' tracks. Indeed, it was a musical stroll down memory lane which had many of the veteran fans, who have been in for the long haul since ''Pretty Hate Machine'' was released in '89, spitting curses at their once-fearless leader as they left the venue.

''Pinion'' and ''Somewhat Damaged'' were the first two numbers used to wake up the teenage-to-mid-twenties, 6,000-strong, black-clad army that had crawled out from under their tombstones for this special event. Although old, the songs were still successful in helping to build the furious atmosphere expected when Reznor makes music. ''Terrible Lie'' and ''Sin,'' both from ''Pretty Hate Machine,'' built up to the first climax of the show, which was capped by ''March of the Pigs'' and ''Piggy,'' two enragers from ''Downward Spiral.''

It wasn't until a half-hour in that Reznor dared to tread tentatively into ''Fragile'' territory. He shouldn't have worried though: ''The Frail'' and ''The Wretched'' were heartily received as the mob suddenly gave up their furious slam-dancing for hypnotic swaying. Those songs, along with new material ''La Mer'' and ''The Great Below,'' proved that Reznor has eclipsed his past skills and can now create an ethereal atmosphere where he once only wanted to prove how angry his beats could be. The show was then raised to a higher level as the latter tracks were accompanied by a film. Images of water were projected onto a massive screen and had a spellbinding effect.

The audience was also treated to the new songs ''The Way Out Is Through'' and ''Into the Void,'' before Reznor finished the set with two earlier efforts, ''Down In It'' and ''Head Like a Hole.'' In the four-song encore, two ''Fragile'' tracks, ''The Day The World Went Away'' and ''Starfuckers Inc,'' got a half-hearty play.

The other general rule for playing oldies at Christmas time is that one must be at least middle-aged. At 34, perhaps Reznor thinks that he has reached this point and that the only way to sell tickets on a live tour--one which is supposed to promote the new release--is to offer his angst-ridden followers songs like ''Head Like a Hole'' and ''Closer,'' rather than his new, intricately layered studio creations. But the ''go with what you know'' content of this tour is a cop-out and the end result is that not only do the record sales suffer, but so do the fans.