STATE COLLEGE, Pa. -- Tie-dyed T-shirts and political slogans made for a heady mixture as the surviving members of the rock band Grateful Dead put on a concert in support of Barack Obama.

Guitarist Bob Weir, bassist Phil Lesh, and drummers Bill Kreutzmann and Mickey Hart hit a Penn State University stage Monday night to play for about 15,000 people.

Although all four regularly tour under their individual names or with their own bands, it was the quartet's first show together since a 2004 reunion tour. Hart, Weir and Lesh had already jammed together in support of Obama in February in California.

Before his set Monday, Hart said in an interview backstage with The Associated Press that he was most impressed with Obama's views on climate change.

"I believe him enough to be able to get up in front of my constituency, these people out there," Hart said, pointing out the door to his dressing room, "and tell them 'I believe.' That's really important. The Grateful Dead does not take this lightly. We've never really done something quite like this."

Andrea Mead, spokeswoman for the Obama campaign in Pennsylvania, said Monday night the main goal was to stir up voter outreach efforts in a critical battleground state.

After Gregg Allman and Butch Trucks of the Allman Brothers Band opened the show, Obama supporters including Penn State assistant football coach Jay Paterno and cornerback Lydell Sargeant took to the stage to endorse him. A taped video message from Obama himself also was projected on a scoreboard.

Then it was on to the main attraction as the lights dimmed and the Dead opened with their classic, "Truckin."' Minutes later, fans were tipping balloons in the air and the arena floor filled with an earthy aroma.

The Dead officially dropped "Grateful" from its name to honor the memory of its lead guitarist and singer, Jerry Garcia, who died in 1995. Mead said the Dead approached the campaign earlier this year offering help in a battleground state with a large fan base.

Brian Cohen, 32, of Wolcott, Vt., drove 10 hours to catch the show. Cohen said he supports Obama but would have attended regardless.

"Obama is really trying to be a good person, which is what Deadheads try to do," said Wolcott, coining the phrase used to describe the Dead's legion of fans. "We try to change the world and be good people, change the world by being good people."

A few people weren't sold on Obama, though, including 38-year-old Jodi Frasier, of Saratoga Springs, N.Y. A registered independent, Frasier said she was concerned about Obama's experience and John McCain's lack of charisma in campaign speeches.

"Right now, I'm still up in the air."