Eminem and the Recording Academy are said to be closely scrutinizing and negotiating the controversial rapper’s possible performance on the Feb. 21 Grammy Awards. “All discussions are predicated on material selection and production ideas,” academy President Michael Greene told the Associated Press. Eminem is something of a double-edged sword for the academy. Though his mega-selling “Marshall Mathers LP” is up for album of the year, its lyrics have outraged various groups, including women, gays and his own mothe r. Then again, all this negotiating might just be in vain. Eminem, who has voiced disinterest in the Grammys, may not show up at all, his handlers have said. Regardless, the show will go on: Madonna, U2, and Christina Aguilera are all scheduled to perform.