It’s Saturday night, and Houston’s East End is full of surprises. I’m looking for a speakeasy tucked inside a mid-century office building when I hear the faint pulse of bongos. Following the beat up a narrow flight of stairs, I emerge into a packed, wood-paneled space called Room 808, where rows of aspiring dancers follow an instructor in flared black pants. “Sway, step together, sway, step together,” she says, tapping out beginner cumbia moves between tosses of her waist-length black hair.