Jerry Seinfeld will appear on "Late Show with David Letterman" next Wednesday night -- not as a guest, reports The New York Times, but as a standup comic. "He just decided that he wanted to do his new act on TV," Seinfeld's spokeswoman, Elizabeth Clark, told the paper. It will be his first appearance doing standup on TV since his 1998 HBO special. "He initially wanted Thursday -- that's his lucky night," said Clark. "But they're pre-empted that night (by the N.C.A.A. basketball tournament), so he took the next closest date." Seinfeld, 46, has made 41 guest appearances on the Letterman show, most recently with former "Seinfeld" costar Julia Louis-Dreyfus. The two sang a duet, "Sixteen Going on Seventeen" from "The Sound of Music."