BOSTON (CBS) – Despite the gray skies and threat of some rain, the usual large crowd came to the Esplanade for Sunday night’s Boston Pops’ rehearsal for the 4th of July.

People lined up for hours for the rehearsal, but the real event is Monday night, where hundreds of thousands of people are expected to flood the city.

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Country singer Martina McBride will join host Michael Chiklis and the Boston Pops on stage for the festivities. McBride is replacing Lionel Richie, who had to back out last week because of strained vocal cords.

McBride spoke to WBZ-TV about her opportunity:

“I was happy to get the phone call. I’m sorry for Lionel. I hope he feels better. My thoughts are with him, but this is just such an honor to be here. This event has been going on for 38 years and it’s obviously a beloved event for everyone in Boston,” McBride told WBZ-TV.

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Chiklis, meanwhile, is thrilled with the opportunity to host the event he used to attend as a kid.

WBZ-TV’s Jim Armstrong spoke to Chikilis:

The other show that fans eagerly await, of course, is the enormous fireworks display.  Fifteen-thousand pounds of pyrotechnics will be set off from barges sitting in the middle of the Charles River.

It took designers six months to create the fireworks display and nine days to set it all up. All that hard work goes into a stunning 20-minute display.

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You can watch the celebration on WBZ-TV beginning at 8 p.m., or listen to the festivities on WBZ NewsRadio 1030, beginning at 7 p.m.