If Colbert’s very first late-night musical treat set the tone, this one set it in stone (and will be one helluva act to follow). Last night Kendrick unleashed a medley of To Pimp a Butterfly songs — “Wesley’s Theory,†“Momma,†“King Kunta,†and “u†— in a purposefully stilted set that reimagined his hits with relentless force; it felt like one long, beautifully tragic poem, a veritable doozy. Here’s Kendrick, the master, at work: