As you head out to see the fireworks tonight, keep in mind all those pyro technicians out there risking their lives for the show.
Also, from a control perspective, keep in mind that many of the shows you see still might be fired using a board full of toggle switches (a "Button Board"--a vast improvement over the "nail" board of the past). Here''s some screen grabs from a great show running on PBS stations this weekend called "321 Fireworks"
These shots were from the 2007 Washington, DC display, and this show was provided by Pyro Shows in Tennesee. All those tehnicians are listening to a special sound track that the public doesn't hear, which has a voice recorded in sync with the music that sounds like a theatrical Stage Manager or a television Director, "Ready 1, Go, Ready 2-4, Go", etc. On each cue, they throw one or more switches.
Of course, there are much more sophisticated ways to shoot fireworks these days, like this popular system from FireOne:
Speaking of safety, the 321 Fireworks show had some great video from Pyro Shows testing the safety of the bunkers they create for their workers (skip to about 3:00 for the best part):