The milkshake has gone sour between Kelis (KEL-ees) and Nas (NAHZ).

Although rapper Nas received backlash over his racial epithet-titled album before switching it to “Untitled,” he says earning a Grammy nomination for his controversial disc encouraged him to keep speaking his mind.

To some, it’s a hurtful racial epithet. For Nas, it’s an album title. The rapper told MTV News that he would indeed be naming his new album after the N-word. And he denied earlier reports that the album’s title would be spelled “N—a,” considered...