This song samples King Crimson's title track from In the Court of the Crimson King (1969) in a most major way.
From his recently released new album W.A.R. (We Are Renegades):
Citizen Cope aka Clarence Greenwood (no relation to Jonny Greenwood) sings the chorus.
The Washington Post did a large feature on Cope in early 2002, calling him "the city's most soulful export since Marvin Gaye." (Wikipedia.org)