Fireworks shows have always been about two things: lighting up the night sky with brilliant colors, and booming explosions that scare kids out of their wits. Behind the scenes, though, much has changed. It\u2019s safer, for one thing. (No more lighting fireworks shells by handheld flares.) And pyrotechnicians employ computers to coordinate their displays and the accompanying celebratory music. The advancements in electronics and computerization has sparked a revolution in pyrotechnics, says Felix Grucci, a partner in Fireworks by Grucci, which has been lighting up the skies since 1850."We have it down to tenths of a second between the timing mechanisms and the music," Grucci says. Grucci\u2019s company handled the pyrotechnics at the past six presidential inaugurals, the Salt Lake City 2002 Winter Olympics, and is on tap to run fireworks shows in more than 75 cities this July Fourth.