With just three days before Election Day, presidential candidate Hillary Clinton stopped in Philadelphia on Saturday night with an entourage of big-name Democrats and celebrities in an attempt to secure the votes of thousands across the region with music and high-energy speeches at a free concert and rally at the Mann Center.

The headliner was fierce Clinton surrogate and pop star Katy Perry, who performed for a crowd of tens of thousands at the outdoor amphitheater in West Fairmount Park.

"I admire so many things about Hilly C," Perry said minutes after hugging Clinton as the performer took the stage to her hit song "Roar," dressed in a sequined American-flag dress. "I agree with so many of her informed, educated policies. . . . And no matter who you are or where you come from, she will be a president for all of us."

Also on hand to help pump up the crowd was television producer Shonda Rhimes and New Jersey Sen. Cory Booker.

The event underscored how crucial Pennsylvania and Philadelphia's suburbs are in this tight election. Before Tuesday, Clinton will have one more visit to Philadelphia - at Independence Mall on Monday with President and Michelle Obama and former President Bill Clinton. Republican presidential candidate Donald Trump and his running mate, Mike Pence, are expected to blitz the state three times.

Saturday's concert was part of a late push by the Clinton campaign to boost the candidate's appeal using widely popular celebrities and politicians - many of whom can help Clinton capture the millennial vote that she has fiercely sought.

Before introducing Clinton to the crowd Saturday, Rhimes, creator of popular shows including Grey's Anatomy and Scandal, took the stage to give an impassioned speech of why she was supporting Clinton.

"That woman has zero chill," Rhimes said, drawing hearty laughs. "Her brain is always working, always thinking, always on."

But before several politicians and celebrities took the stage to stump for Clinton - including U.S. Rep. Bob Brady, U.S. Senate candidate Katie McGinty and former Secretary of State Madeleine Albright - thousands of supporters, decked out in Clinton shirts and hats, flooded the lawn of the venue, which at capacity, holds 14,000. Pop songs blasted over the speakers, as dozens danced and swayed. The mood was jovial and lighthearted.

On Friday at a similar event in Cleveland, Clinton was joined on stage by Beyoncé and Jay Z, who praised the candidate before headlining a concert. In Hershey, Pa., on Friday, Trump took the stage in front of more than 10,000 without the comparable big names that Clinton has aggregated - a contrast the candidate made sure to point out.

"By the way, I didn't have to bring J. Lo or Jay Z - the only way she gets anybody," Trump told the crowd Friday. "I am here all by myself. Just me. No guitar, no piano, no nothing."

The starkly different eleventh-hour campaign strategies by the candidates underscore just how different their runs have been. Trump - selling himself from the beginning as the outsider, the underdog - has made it clear to supporters he has been able to go at the presidency alone, without much of the Republican establishment that has denounced him along the way.

Clinton, by contrast, has recruited A-listers and powerful Washington names to scatter across the country to try to boost her reach and appeal.

Before the show Saturday, Clinton supporter Dave Levy, 43, of Chalfont, said that after a long campaign unlike any other, he was excited to vote for the first woman major-party presidential nominee. With him, he brought his 9-year-old daughter, Julia Levy, a Katy Perry fan - and an even bigger Clinton supporter.

"She shows me that anything is possible as a woman," Julia said. "That a woman can be a politician, a scientist, anything."

As for her dad, Levy, an elementary school teacher, said he was voting for Clinton, "the best candidate for education."

Entry to Clinton's rally Monday at Independence Mall, where Jon Bon Jovi is set to perform, will begin at 4 p.m. Trump's next rally in Pennsylvania is scheduled for Sunday at 8 p.m. in Moon Township in Allegheny County. He will be in Scranton on Monday.