A lot of pop expected at July 4 Spectacular

With the Boston skyline as his stage and more than 15,000 pounds of pyrotechnics as his players, Tucker has just two more days to perfect his ninth Boston Pops Fireworks Spectacular.

“Everybody in my business wants to do this show,’’ Tucker said, holding a firework shell about the size of a human head as he stood on “steel beach,’’ the fireworks barge sitting in the middle of the Charles River.

Tucker said planning for this year’s show began about six months ago and includes effects from all over the world. Next week, he will travel to Spain and move on to France and China, all in search of the best fireworks he can find for future shows.

As he spoke, he held in his hands a Japanese-style shell, a silver spider, about 10 inches in diameter, that will shoot into the air and burst out 1,200 feet across — the length of more than three football fields.

The silver spider is one of 80 “big guys,’’ Tucker said. It will be loaded into a metal tube and packed with sand into a trash-can sized tub with a computer hook-up. At the push of a button, the technician can light the black powder, transfer energy to a charge and send the shell crackling into the air as rows of tiny stars burst out and fall back to earth.

He tests each type of firework twice, once where he buys it and once in a dry lake bed in California. After that, he choreographs the show by memory.

“This is an A-type personality job,’’ Tucker said.

During the show, a few crew members will be on the barge, sheltered by metal boxes that vaguely resemble dumpsters but will house intricate controls. The show may look enchanting when viewed from the shore, but on the barge, the process is loud, dangerous and “out of control.’’

Tucker said he used to be on the barge, but he will be directing from a dock by the Hatch Shell this year, so he can watch and give cues.

“I miss it,’’ Tucker said of being on the barge. “You don’t do this job for a minute without liking it.’’

The whole show has more than 4,500 digital cues, but Tucker still takes a minute to appreciate his handiwork.

“There’s that one moment when I take out one earpiece and listen to the crowd,’’ he said.

The fireworks display will last about 20 minutes and be set to music by Michael Bublé, Lady Gaga, and Celine Dion, to name a few.

The entire Spectacular, which will include the annual Boston Pops concert at the Hatch Shell and a performance by country star Toby Keith, costs about $3 million, said Steve MacDonald spokesman for Boston 4 Productions. Liberty Mutual pays for more than half of that, but MacDonald declined to release the fireworks budget.

Production is underway at the Hatch Shell, where the stage extension, lights and a few giant screens are already in place.

Producers said they had a long way to go, but that the show will have a few surprises this year, one of which will be “big.’’

“There’ll be a lot of pop,’’ said producer Pam Picard of B4 Productions said. “That’s the hint.’’

The oval opens at 9 a.m. on the Fourth, and 9,000 people are expected to fill it by the time the concert starts at 8:30 p.m., MacDonald said.

Sydney Lupkin can be reached at slupkin@globe.com.