NIN is primarily Trent Reznor. He started out in the late 80's, working on his own. After recording Pretty Hate Machine, he realized how hard it would be to play live, so he recruited other members: James Wooley on keyboards, who left in 1994, but was replaced by Charlie Clouser. Richard Patrick was the tour guitarist for NIN; while Brian Leisgang handled some sampling and programming duties.

Currently, the live band is composed of:

Trent Reznor. Vocals, guitars, keyboards, etc.
Danny Lohner. Guitars, bass, keyboards.
Sean Beavan. Sound man, who can almost be considered an extra live band member.
Jerome Dillon. Drums.
Robin Finck. Guitars, from 1991-1996, then eft to work with the Cirque Du Soleil, but returned in 1999.

Past members:

Chris Vrenna. Drums and official second member of the band. Chris left in late 1996/early 1997 to pursue some other interests. He currently does still work with Reznor on his projects.
James Woolley. Keyboardist through most of the 94-95 tour.
Richard Patrick. Guitars for 89-91 tours. Now in Filter, with Brian 'Moonking' Liesegang, who also has done production work with NIN.
Jeff Ward. Drums. Died in the making of The Downward Spiral. Rest in peace. Was also in Ministry, Lard and Low Pop Suicide.
Martin Atkins. It has been said that Atkins drummed at a few shows.
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