For Netflix’s “Narcos,” which follows the rise of the Colombian drug cartel, composer Pedro Bromfman wanted to infuse the score with an authentic flavor without relying on cliched Latin rhythms.

To help achieve that goal, he recorded sounds of Colombia’s traditional instruments — including the ronroco, charango, accordions and traditional flutes — and put them into a computer program, where he could manipulate them.

Bromfman had an unusual advantage: He began the scoring process before scenes were shot. This gave him time to experiment, and allowed musical ideas to “marinate,” as he says, while he created themes for the morally complicated characters. His fleshed out score was a major asset in the post suite, where editors were able to custom-design music instead of using temporary cues during early cuts.

“People get used to listening to the substitute themes in the tracks, so it gets tough to provide something different,” Bromfman says. “(Fortunately) we didn’t use sound libraries. Everything was created specifically for this world. It’s very unusual to have such an opportunity in television.”