If you ever wondered why celebrities are embarrassed to show 'Before They Were Stars' footage or photos, look no further than this recently unearthed footage of Nine Inch Nails rocker Trent Reznor covering Billy Idol's 'Eyes Without a Face.' His past has caught up to him, and from the looks of things it brought a full can of Aqua Net along too.

Reznor has had many hits since Nine Inch Nails debuted with 'Pretty Hate Machine' in 1989. Perhaps his most famous (until now?) would be 'Closer' from 1994's 'The Downward Spiral.' A sampling of the song's lyrics for those too young to remember include this opening stanza: "You let me violate you / You let me desecrate you / You let me penetrate you / You let me complicate you."

Pretty graphic stuff. As it turns out though, Reznor isn't all sex and violence. In the following recently uncovered video from DangerousMinds.com, Reznor covers Idol's 'Eyes Without a Face' in a very faithful manner. For comparison's sake, take a gander at a few of this song's lyrics: "Now it makes me sad / It makes me mad at truth / For loving what was you." It's like seeing Ozzy Osbourne in Dockers, or Chuck Norris in a diaper.

Reznor shows off some pretty sporting dance moves as he works his magic on the keyboard. One naturally wonders who the band backing him is, and if they were asked to join him on the album? That seems unlikely giving the rocker's policy of doing it himself. Metal Insider reports that Reznor was part of a Cleveland, Ohio band called The Urge in the mid-80s. He also played with a group called Option 30. Both of those ensembles seemed to have gotten deep-sixed before Reznor released 'Pretty Hate Machine.'

In reality, '80s Ohio probably wasn't ready for the style Reznor would soon make famous. It's not difficult to see how Billy Idol may have influenced a future generation of electro-rockers. Idol certainly pushed the boundaries as did Reznor years later. We're willing to forget and forgive, but that's 'Strike One!,' Reznor.

Watch Trent Reznor Sing Billy Idol's 'Eyes Without a Face'

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