Pharrell says his rap-rock trio "experimented" with an additional band mate, singer Rhea. Says Pharrell: "She needed her own band to do the kind of music that she does, which is R&B."
The 37-year-old Pharrell is producing Rhea's album. He says it is "turning out incredible." Rhea performs with her band Jealous Lover.
N.E.R.D's fourth album, Nothing, is set for release on Sept. 7. Pharrell says the disc was inspired by music from the late '60s and early '70s.
The CD's lead single, the up-tempo groove "Hot 'n' Fun," features Nelly Furtado.