In the wake of the recent national tragedy, President Bush is urging Mariah Carey, Michael Jackson, and other singers to resist the urge to record mawkish, insipid all-star tribute ballads. 'To America's recording artists, I just want to say, please, there has already been enough suffering,' Bush said. 'The last thing we need right now is a soaring Barbra Streisand-Brian McKnight duet titled 'One For All.'' Reports that the FBI had confiscated several notebooks and audio tapes from Diane Warren's home could not be confirmed as of press time. 