Hours after teasing what all signs point to being his upcoming release, IV, Kendrick Lamar has debuted its first single. “The Heart Part 4,†which appears on iTunes with IV’s cover art, marks one of Lamar’s first major projects since his surprise untitled unmastered dropped last year. The song is a dense track, replete with musings on Donald Trump, politics writ large, and Lamar’s conviction that he is the greatest rapper alive. Best of the best or no, it’s good to have him back. Listen to “The Heart Part 4†below.