As soon as the smoke cleared from last year's event, Souza and his brother set to work on planning for 2015. They traveled to Washington, D.C., met with event planners, even sat in while sound engineers mixed new music.
"It's me and my brother sitting there, telling them, 'We really like that,' " Souza recalls, "or maybe, 'We can have some more cymbals here 'cause we could have this great big kaboom go on at that very crescendo.' "
And then, of course, there are the firework shells themselves. Round like a basketball, covered in brown paper and filled with little colored balls called stars, the shells make the effects that, in turn, make the Macy's show famous. And there are a lot of them: Souza says that in one show, 50,000 fireworks will go off for 25 minutes.
"And all this happens in seconds — milliseconds," he says. "The explosion will push the stars across the sky, burst into a single color, transition from red to white to blue — or twinkle or whistle or whatever the effect is."
All of this is planned out with tiny blue dots — thousands and thousands of annotations — crowded onto a spreadsheet on Souza's computer. The blue dots, each one representing a single fireworks effect, splay out like music notes on a page.
It may sound exceptionally complicated, but fireworks are in Souza's blood.
"We grew up — not just our job, that's our family," Souza says. "That's what we always grew up with." Even at 12 years old, Jim Souza was already working on professional fireworks shows. But, as he's quick to point out: "It's called firework, not fire fun. And so, yeah, when it's hot and you're digging trenches: 'Can I do something else, Dad?' "
This Independence Day in New York City, dozens of Pyro Spectaculars technicians have been checking every wire, every computer connection, every shell. After all, they only have one shot to get it right. It's a lot of work, and a lot of pressure, but remember:
"It's just cool," Souza says. "It's the coolest thing ever."
Copyright 2016 NPR. To see more, visit http://www.npr.org/.