Kendrick Lamar often sounds desolate on To Pimp a Butterfly, but he never sounds alone. His records are swarming with squabbling voices that have something—usually indignant or deflating—to tell him. Lamar, of course, is responsible for them all: On “u”, he's a sobbing family member, excoriating Lamar for neglect; on "You Ain't Gotta Lie", he plays his own mother, admonishing him for preening. Listening to the album sometimes feels like standing in the middle, unnoticed, of a large quarrelsome crowd—a rally, perhaps, or someone's family reunion. Through all these spaces, Lamar is always visible, but he is often not at center stage.

As the cast of characters proliferates, so do Lamar's flows: He sometimes seems to be rapping in three voices at once, an internal monologue mixed up with an external one and dipped in the ambient chatter he absorbs through every room he steps in. He has almost destroyed the beat in his music, as if to acknowledge that the most important stories we tell are usually the messiest, the ones that don't arrive in straight lines. The music he's chosen—cramped, hectic jazz—packs more sonic information into a small space than any other popular form, and Lamar crams every available space with his words.

He's always been a wordy rapper, one more drawn to long chains of unfolding thought than tight, pithy quotables, and on Butterfly he is purposefully offering us more than we can absorb. In hard technical terms—breath control, complexity of rhyme schemes, variation of flow—Lamar is the best rapper working, but how he deploys that skill on Butterfly is far more interesting than the skill itself. He seems to be aiming for the point where all knowledge has been interrogated, all corners of an idea exhausted. On the outro to "Momma", he brings the fader down on himself while still rapping furiously, his voice doubled up. On "For Free?", he leaps off of piano sforzandos until there is no legible forward motion anymore—try nodding your head to it and see what happens to your neck.