The late afternoon sun was beginning to settle into a one of those early spring New York City chills when I heard it behind me:

Woooo! Wooooohaaahoooo! Wooooo! A brief pause, and then, alarmingly, another Wooo-woooo!

The sound, a kind of cross between a yodel and a scream, was coming from Michael DeLuca, a 21-year old New York University student standing with his arms flung high in the air. He had a camera slung around his neck and a Bernie Sanders sticker on his chest. DeLuca and his friend Cristina Gnecco, also 21, were flush up against a metal barricade, surrounded by some 27,000 people who gathered in Washington Square Park last week to support Sanders before tomorrow's New York primary.

In a city that's home to the bright lights of Broadway, arguably the hottest tickets in town (ok, with the exception of Hamilton) have been Sanders' rallies.

But it wasn't the Vermont senator that DeLuca was positively losing his shit over at that very moment. It was Vampire Weekend, the indie band whose frontman, Ezra Koenig, has been one of Sanders' most vocal supporters on the campaign trail, tweeting so often about the Sanders campaign that he recently solicited ideas from his followers for other topics to tweet about.

Koenig and the band have travelled from Iowa City to Chicago performing at Sanders rallies, and on this day they were back in their hometown of New York City, preparing to pump up yet another crowd.

For DeLuca, the chance to see Vampire Weekend perform right in the middle of his college campus was a major factor in his decision to show up.

"It was half the reason? Yeah, half the reason for me," DeLuca said. "Big Bernie supporter, but I love Vampire Weekend."

He wasn't the only one. "When I found out Vampire Weekend was playing, I was like ok that just gave me another reason to skip class today," said Diego Llaca, a 20-year-old NYU student. "Yeah I’m one of those."

Issie Lapowsky

In a city that's home to Radio City Music Hall, Madison Square Garden, and the bright lights of Broadway, arguably the hottest tickets in town (ok, with the exception of Hamilton) have been Sanders' rallies. That's partly because of Sanders' well-known ability to draw a crowd, but it's also thanks to the stacked lineup of indie acts turning out to perform on behalf of Sanders.

"People love music, don’t you think? It gets the crowd revved up," said Sanders campaign manager, Jeff Weaver. "It’s fantastic. We really appreciate all the musicians that come out for us."

And there are certainly a lot of them. On Wednesday it was Vampire Weekend and Dirty Projectors. On Sunday it was Grizzly Bear. And tonight, it'll be TV on the Radio. And that's not counting the many other artists who have stumped and performed for the Sanders campaign in the past, from Run the Jewels rapper Killer Mike to Thurston Moore of Sonic Youth to Jeff Tweedy of Wilco.

Taken together, Sanders' campaign is like the Pitchfork homepage come to life, filled not with giant stars like Katy Perry or Beyoncé (They're #withher), but with artists who some might say are outsiders to the musical establishment.

Indie Cred

At least, Ed Droste, lead singer for Grizzly Bear, would say that. According to Droste, who performed for a record-setting crowd of 28,000 at Sanders' rally in Brooklyn yesterday, there are parallels between Sanders' contempt for money in politics and the influence of money in the music industry.

"The people with the money get to decide who’s on the radio," Droste said, adding that he believes the reason so many indie artists have lined up behind Sanders "is because none of us feels beholden to a giant corporate company."

Droste says he's always been politically active, campaigning and voting for whomever the Democratic nominee has been. But he says that Sanders has given voice to some of the frustrations Droste has about the Democratic party itself, particularly the influence of money in politics. So he started speaking out about his support for Sanders. Before long, the campaign reached out to him to see how they could work together.

'Worst case scenario: some Vampire Weekend fans who won't vote for Bernie came through. At least they saw the rally.' Ezra Koenig, Vampire Weekend

"I think we would all be better off if we could extract money, especially from politics, because politics is truly the thing that affects everyone's life the most," he says. "That's just not going to happen under any other candidate but Bernie Sanders."

Koenig agrees. "Bernie's a uniquely inspiring candidate," he told WIRED. "I wish there were more candidates with his legislative experience, voting record, and long-time independence from the two-party system, but there aren't."

"An independent with an admirable record of integrity joining the Democrats at the best possible moment presents a unique opportunity for change," he added.

For people like DeLuca, these types of endorsements are crucial. "Not everyone is a politics major," he says, though he happens to be one, as well as vice president of NYU's Young Democrats. "When you have people you respect and see them going for specific candidates, that carries a lot of weight for a lot of people, and Ezra Koenig is someone I respect."

I'm With the Band

Of course, inviting these stars to open for Sanders also invites the possibility that, well, not everyone will be there for Sanders. Even DeLuca said he was only there 50 percent for Sanders. No doubt, there are plenty of people for whom that number is even lower.

Koenig says that effect doesn't bother him too much. "Anything that increases visibility is a net positive. Musicians supporting Bernie gets music publications writing about Bernie more, it familiarizes music fans with Bernie as a candidate," he said. "Worst case scenario: some Vampire Weekend fans who won't vote for Bernie came through. At least they saw the rally and heard him speak."

And those people are likely few and far between. According to Koenig, the biggest difference at the rally in Washington Square Park was that the people in the front row weren't Vampire Weekend fans. That crew was in the back. Instead, he says, the front row consisted of members of the Communications Workers of America, who, just that day, had gone on strike against Verizon. Sanders joined them in the picket line.

"They were mostly middle-aged men, and when we came out they were yelling for 'Freebird' and Zeppelin," Koenig said. "I loved seeing them though. I'm the son of a New York City union member and a former member of the teacher's union myself."

For Droste, it would likely be a different sort of show, as well. When I talked to him on Friday, he hadn't yet met Sanders. This time, he was the one hoping to get a selfie with the headliner.