"You are the last Colbert Report musical guest. Honored to have you on, but keep in mind: Paul McCartney , R.E.M., Jack White , and Nas were your opening acts," Stephen Colbert cleverly quipped at Kendrick Lamar during their pre-performance interview on last night's show. Lamar premiered a brand new "Untitled" track reportedly produced by French beatsmith Astronote ; its world-premier performance was delivered by a pick-up band consisting of bass virtuoso Thundercat , Terrace Martin on sax, and back-up vocals from Soulquarians affiliate Bilal and Sonnymoon sogstress Anna Wise . In stark contrast to Kendrick Lamar 's previous Isley Brothers -indebted "i," "Untitled" is more of a sparse experimental, Jazz -leaning affair, which seems to be a multi-faceted narrative; "In Lamar's story, an Asian man tells him to worry about his health and not his career, an Indian man recommends he invest in real estate, the black man rev...