With Lamar's previous album, 'Good Kid M.A.A.d City', lauded as one of this fledgling Century's best, the level of expectation on its follow up was sky-high. How do you proceed after such a triple A-rated straight-up hip hop smash? Get afflicted by the (P)funk, that's how. Channelling the psychedelic stew of Parliament / Funkadelic, 'To Pimp A Butterfly' positions Lamar along the higher branches of rap's genre-busting evolution (see also The Roots’ 'Phrenology', Common’s 'Electric Circus', Q-Tip’s 'Kamaal the Abstract', André 3000’s 'The Love Below'). The expansive scope of Lamar's vision also runs to a live studio band featuring Robert Glasper, Flying Lotus' fretless bass maestro Thundercat and producer /sax player Terrace Martin, who add free jazz backing, pulling the music in another direction.

Lyrically the album walks in the footsteps of the socio-political commentary of Curtis Mayfield and Marvin Gaye, but in the post-Ferguson era of continued police brutality towards African-Americans, Lamar's anger burns bright. Less 'What's Going On', more ' The Predator'. He offers a thoughtful and thought-provoking exploration of what it means to be a black man in America today, often introspective, but never naval-gazing.

Inspired and inspiring, 'To Pimp A Butterfly' is an adventurous and challenging album, and one that can be added to the essential hip hop list.