When DJ Cassidy got the call last month from Democratic National Convention producers, he knew he was probably in for a cool experience. But he had no clue he’d be sparking one of this summer’s most viral moments.

Cassidy’s Tuesday night set at Chicago’s United Center — where he accompanied the state-by-state roll call with a selection of related songs — became the talk of the convention Wednesday, drawing reams of news coverage and social media reaction.

It was a loud, enthusiastic response that Cassidy “one thousand percent” didn’t anticipate, he told the Detroit Free Press.

“I knew this was certainly going to get some attention and be a special moment, one of the more fun moments,” Cassidy said Thursday. “But in no way did I have any expectation of it striking such a chord. I think at the end of the day, that’s what it did — struck an emotional chord through the music and through the way it was put together to hit the people in the arena.”

The veteran New York-born DJ has spun for everyone from Beyoncé to Barack Obama and, in more recent times, become known for his popular “Pass the Mic” sessions, launched online during the 2020 pandemic lockdown and later repurposed into a live touring show.

Need a break? Play the USA TODAY Daily Crossword Puzzle.

Still, he woke up Tuesday “with a bit of nerves” ahead of his prime-time segment. The 75-minute, 57-track musical session had been plotted out in close collaboration with Democratic National Committee officials and state delegates, becoming a mix of state anthems, music by artists associated with specific locales and universal songs intended to capture the evening’s celebratory energy.

“The more collaborative this process was, the more authentic and sincere and genuine it would be,” Cassidy said, noting that he'd been enlisted by the DNC after President Joe Biden "passed the mic" in July to Kamala Harris as the Democratic candidate.

Embedded content: https://www.usatoday.com/story/entertainment/music/2024/08/21/democratic-national-convention-2024-music-performers/74892920007/

Many of the DNC selections were self-evident — songs like “Sweet Home Alabama,” “California Love” and “Texas Hold ’Em,” along with “Empire State of Mind” for Cassidy’s own New York stomping grounds. For New Jersey, it basically had to be Bruce Springsteen (“Born in the U.S.A.”); for Minnesota, Prince (“Kiss”/“1999”).

But other choices were perhaps less intuitive: Tom Petty’s “Won’t Back Down,” for instance, was picked when Florida representatives made it clear the Gainesville native’s classic had become a grassroots anthem in the Sunshine State. .For a place such as Michigan — which has an expansive musical legacy across genres — the possibilities were abundant. But sometimes the songs selected themselves, Cassidy said, and that was the case with Eminem’s “Lose Yourself.”

“Detroit is Motown, so you could have gone to so many amazing places with that,” Cassidy said. “But ‘Lose Yourself’ was honestly instinctual for all of us from the beginning. We felt like it was the perfect song. It all goes back to feeling. Musically, it has an emotion that makes you feel like the boxer walking out to the big fight. You’re putting your gloves on, putting your robe on, ready to go. It’s anthemic.

“Eminem really created an ‘Eye of the Tiger’ or ‘We Will Rock You’ for our generation,” he continued. “I felt a song like that would react in a big way inside the arena, and that would translate through the TV screen.”

Michigan wound up supplying songs for three other states: Stevie Wonder’s “Signed, Sealed, Delivered” (Connecticut), Aretha Franklin’s “Respect” (Maryland) and the Romantics’ “What I Like About You” (South Dakota).

Those were among the cases where Cassidy, lacking an obvious homegrown option for a given state, turned to music that “exuded the themes, emotions and spirit of the night,” he said. When he took on the DNC project, he’d compiled a list of such songs — music representing “respect, freedom, unity and celebration” — even before diving into geography.

Some of Tuesday’s tracks turned out to have unplanned relevance. Among them was “Respect,” a song embraced by Maryland’s Speedo Sims before it was made famous by Otis Redding and Franklin. That trivia tidbit was highlighted by keen-eared Marylanders following Cassidy’s set.

“I would love to take credit,” the DJ said. “But it wouldn’t be first time in my career I experienced that kind of coincidental serendipity.”

His personal highlight of the night? It came with the set’s only instrumental song, the Alan Parson Project’s “Sirius,” long used by the Chicago Bulls as intro music at the very same United Center. Like “Lose Yourself,” the track has a “when we fight, we win” energy, Cassidy said.

“I personally loved hyping the crowd during that one,” he said.

All told, Cassidy’s set spanned seven decades of music, from Sam Cooke to Chappell Roan, and “nearly all genres, all walks of life, all demographics,” as he put it.

From his DJ deck, Cassidy could feel the buzz build inside the United Center as the audience figured out what was going on.

“They were almost waiting for the next song, guessing what it could be, which really is that element of surprise a DJ relies on for excitement: What's coming next? When will the record drop? What will it be?” Cassidy said. “That's at the foundation of what makes it exciting to listen to a DJ.”

From a technical perspective, the set presented unique challenges. Typically, as DJs segue from one song to another, they narrow down a key exit point — maybe the finale of a rousing chorus, or the end of a sing-along line.

But at the DNC, Cassidy would be at the mercy of the state delegations, whose speaking segments might run a bit long or short.

“So I had to come up with a musical roadmap that would allow me to exit and enter each song at various points that made musical and emotional sense,” he said. “I needed almost infinite possibilities.”

Nearly two days later, Cassidy was still beaming with the success of his Tuesday night work. He’d read thousands of online reactions.

“And you know what’s really cool? I haven’t seen comments saying, ‘Why didn’t you pick this song?’ That’s something you’d expect to see, especially on the internet,” he said. “It almost seemed like people innately appreciated the song that represented their state in their own way and felt the love. That was a goal, and it’s been so amazing to see the reaction.”