I've always had a deep respect for freestyle hip hop and although I don't enjoy all of them, some songs completely blow you away (I bet you also remember TaiTheGaw & Tay Rob's "Batcave Freestyle").
Here comes another duo - US rappers Crowded Places & Ryan Cabana. Their conscious & deeply lyrical "Pie Freestyle" will not only mesmerize you with their flow - which turns Spanish for a bit in the 2nd half - but also with the woozy guitars & keys alongside the slow beat.
Both have pretty different techniques but complement each other so well - making this a song that can't get boring despite its mellow vibe.