Sometimes a song is so catchy, with a groove so bouncy and ebullient, that choreography becomes second nature.

For Baltimore’s TSU Dance Crew, that was the case with “Boots on the Ground.”

Dancer Ryan Daly, who goes by Ayo Shag, was blown away by how well local favorite move the Park Heights Strut fit the viral track.

“Every time I listened to it, I kept laughing because it’s like, bro, it just goes so well with this song right now,” the Essex native said of the recent line-dancing R&B hit by South Carolina’s 803Fresh.

“We added the Old Bay on there,” chimed in Terry Wedington, better known as TSU Terry.

Alongside Charvez Mackall, aka TSU Rum, the trio birthed the Baltimore dance to a song that has caught fire across the country. “Boots on the Ground” has spent the past five weeks atop Billboard’s R&B Digital Song Sales chart, and notable celebrities — from Beyoncé and Jennifer Hudson to Michelle Obama and Kamala Harris — have been seen dancing along to the buoyant single. The official music video, released two weeks ago, has already racked up more than 4 million YouTube views.

TSU’s spin on the song has played its own part in the single’s growing success, with clips of the trio performing the dance earning millions of views across TikTok, YouTube Shorts, Instagram and Facebook.

“It just started going crazy,” Ayo Shag said.

The first “Boots on the Ground” dance, created by Georgia’s Tre Little, went viral in part because of its use of hand fans — a cowboy hat tip to the song’s “Where them fans at?” lyric. TSU’s version nods to the original but eschews any props, with the dancers instead using hand claps and foot stomps in sync with the song’s percussion.

They also incorporate other moves that have long been staples of Baltimore club dance music, from the Baltimore two-step to the heel toe.

“Baltimore ate this! Left no crumbs! Such obvious joy,” one YouTube commenter wrote. “Love Baltimore boots on the ground! Aloha from Hawaii,” wrote another.

Why does the Baltimore version resonate with fans from all over? “We give a smooth, energetic type of feel to the dance,” TSU Terry said. “The dance was great before we touched it, but as soon as we added our little spin on it, I feel like we added a bit more flavor into it.”

803Fresh took notice, inviting the trio to perform the dance alongside him earlier this month at Pier Six Pavilion during DJ D-Nice’s Club Quarantine 5 Live concert.

“He actually already knew who we were and was so appreciative of what we had done,” Ayo Shag said. “Without hesitation, he was like, ‘Y’all trying to come on stage with us?’ ”

“Boots on the Ground” is the latest viral moment for a dance crew that’s been on a roll lately. “Roll Call,” TSU Terry’s song with TT the Artist and Mighty Mark, recently became a “Fortnite” emote. On Wednesday night, the crew danced during halftime of the Washington Mystics-Indiana Fever WNBA game at CFG Bank Arena.

The group continues to win over new fans because the dancers lean into their hometown pride with infectious joy, TSU Rum said.

“Every time they see it, they be like, ‘Oh yeah, that’s definitely Baltimore right there,’” he said. “Because we actually made ourselves known in the world with our unique moves, our style. So when they see our energy, they’re attracted to it.”

Local residents interested in gaining some of TSU’s aura are in luck: The trio is hosting a “Boots on the Ground” dance class on Saturday, 2-4 p.m., at Essex’s Underground Dance Academy (130 Eastern Blvd.). There’s no need to be an expert dancer — just be ready to let loose.

”The biggest thing we say is just come out and have fun with it,” Ayo Shag said.