Before parsing the script on Kendrick Lamar's latest record—released by surprise last night—you have to dig into the score. To Pimp A Butterfly is the major-label actualization of a jazz scene that's been fostering in Los Angeles for years, with young inspired composers reimagining Miles, Coltrane, and Sun Ra in a post-rap world. Lamar tapped a spread of keyboardists, arrangers, and specialists to give the album a sense of living, breathing momentum, with songs pivoting mid-movement and ebbing in and out of interludes. While names like Boi-1da and Pharrell barely squeeze in a credit, these are the players that have shaped the record's forward-leaning sound.