NEW YORK, NY (CBS NewsPath) — Tonight, an estimated 16,000 firework shows will be held across the country. But how do pyrotechnicians create all those beautiful shapes and colors in the sky?

In an interview with Paul Smith, President of the Pyrotechnics Guild Internation, CBS News’s Michael George learned the science behind fireworks magic.

“You’re seeing chemistry in action,” Smith said.

Fireworks are basic composition, they have an oxidizer and a fuel for them to work, according to Smith. When it comes to colors, it’s just different chemicals being used to showcase a specific color.

“Strontium is a predominant one used for red, barium is often the key component in green color situations, copper is for blue,” Smith said.

When it comes to these big shows, such as the Macy’s spectacular, each firework shell must be precisely packed and time to the second to be synchronized with music.

Gary Souza, a Macy’s Fireworks Desinger, said their production involves 48,000 shells, that end up creating 17 unique patterns in the sky

“Making shapes with fireworks has become more and more of an art, in a sense that you have to strategically place the shells, the stars within the shell,” Souza said.

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And a tip from the pros. They say the best seat to watch the fireworks is usually not close up. They say give yourself a little distance so you can take in the entire display.)