Lamar's duet with SZA samples Luther Vandross' 1982 hit "If This World Were Mine." The song was written by Marvin Gaye, who himself recorded it in 1967 as a duet with Tammi Terrell. This is FRESH AIR.

With no warning—and because he can—Kendrick Lamar dropped his new album GNX on Friday afternoon. The record takes its name after the 1987 Buick featured on the album’s cover, the same year Kendrick ...