On a Thursday, at twilight, the intersection is quiet. Few cars go by. A spotless arepa stand offers Colombian corncakes on one corner, a tiny grocery store sells soda and candy on the next, and tangerine-colored houses occupy the other two. It would be easy to ignore the simple white banner stretched from one telephone pole to the other. Blink and you’d miss a two-meter round stage, cobbled from scrap wood that sits on the sidewalk. But ignoring these clues would be a mistake. Tomorrow night, the corner of 52nd and 50th streets in Barranquilla’s Barrio Abajo will be the site of the best block party in Colombia’s capital of music. No salsa, no champeta, no merengue. Nothing but the folkloric cumbia and its closest cousins. At 11 p.m. on Fridays, this intersection becomes a tropical mosh pit—that is, one with rhythm. If they sold tickets, it would be the hottest show in town.