PORTLAND, Maine — Members of the hit indie pop band fun. and Hollywood star Brad Pitt added star power to the campaign for same-sex marriage Wednesday, playing a promotional Portland concert and advocating for a “Yes on 1” vote less than a week before Mainers go to the polls to decide on the controversial referendum.

The band’s arrival in Maine’s largest city came the same day as A-list actor Pitt announced a $100,000 donation to same-sex marriage campaigns in four states, including Maine’s, highlighting the final publicity push for “Yes on 1” advocates approaching Election Day. The two headline-grabbing moments also come on the heels of recent efforts by opponents of Question 1 to amplify their own message with high-profile statements and events.

Former Christian Civic League head and long-time same-sex marriage opponent Michael Heath was among those who turned up the heat on Monday during a rally at the State House in Augusta, calling same-sex marriage “intrinsically harmful and evil.” That followed a declaration last week by Bishop Richard Malone, recently of the Roman Catholic Diocese of Maine, that a “Yes” vote on Question 1 is “unfaithful to the Catholic doctrine,” his most forceful words of opposition yet.

But celebrity same-sex marriage supporters Wednesday urged Mainers to think of Tuesday’s vote as a chance to end discrimination against gays and lesbians. In an email to members of the Human Rights Campaign, a top nationwide GLBT advocacy group, Pitt said he made his donation in part so he wouldn’t have regrets after Election Day — and he said voters should be similarly motivated in the days ahead.

“It’s unbelievable to me that people’s lives and relationships are literally being voted on in a matter of days,” wrote Pitt. “If you’re like me, you don’t want to have to ask yourself on the day after the election, what else could I have done?”

Jack Antonoff, guitarist of fun., echoed that sentiment when talking to reporters in Portland before his band’s sold-out concert, which was scheduled for an 8 p.m. start at The State Theatre. The three-member New York City-based band is best known for two top-five platinum singles. “We Are Young” and “Some Night.”

Antonoff said all three band members are straight, and said no managers or marketers have tried to temper their outspoken stance supporting gay rights.

“It’s not so much people telling us not to do things, but we ask a lot of the organizations we work with, the people we work with, the people who work with us, the bands we tour with — everybody — [to be supportive]. It’s not something we want to be shy about,” Antonoff told the Bangor Daily News. “Sometimes people get a little bit timid.

“But I tell the story of my grandfather,” he continued. “He marched with Martin Luther King, and how amazing is that for him to be able to tell his grandkids [about that]? What was that like when African-Americans had less rights? [My grandfather can say] ‘It was horrible, and I was right there fighting against it.’ And we all know where this is heading. It may be uncomfortable to be in challenging situations, but do you want to stand on the right side of history or, years from now, look at your grandkids and say, ‘It was terrible, and I didn’t do as much as I could have.’”

Antonoff said he isn’t trying to change the minds of ardent same-sex marriage opponents, but rather motivate Mainers who are leaning toward a “Yes” vote to be more active.

“It’s really about all those who have their heads and hearts in the right place, but aren’t speaking up,” he said.

Matt McTighe, chairman for the same-sex marriage campaign “Mainers United for Marriage,” said the advocacy of pop stars like fun. help highlight the issue — and the importance of voting on it — for a younger audience.

“I think it just calls attention to the fact that there is an election coming up, and there’s still a lot of work that needs to be done,” McTighe said Wednesday at The State Theatre. “A lot of younger voters may not be thinking about that — they may be thinking about other things, like getting back to school. But this calls attention to the fact that we’re right on the cusp of achieving marriage equality.”

Matt Hutson, campaign director for Protect Marriage Maine, which opposes the same-sex marriage referendum, expressed confidence Wednesday evening in the ability of Maine voters to discern credible advocates.

“On an issue as important as marriage, I’m confident that Mainers will give more credence to the Rev. Billy Graham and Bishop Richard Malone, who support traditional marriage, in comparison to a band called fun.,” said Hutson.

A call to Maine4Marriage, another group advocating for “No” votes on Question 1, was not returned Wednesday.

Seth has nearly a decade of professional journalism experience and writes about the greater Portland region.