Kendrick Lamar and SZA’s Grand National Tour is already a runaway success. The co-headlining jaunt has captured two artists at their commercial zeniths and is the biggest co-headlining tour of all time,

What to say about these two? Kendrick is the biggest rapper in the world. His albums light up the charts with their wit and shade; his anthems, like last year’s Drake-takedown (Drakedown?) “Not Like Us” are instant hits,