Bangor got a taste of the eclectic musical mix the National Folk Festival’s expected to bring to town next month as the South American band Inca Son warmed up a riverfront audience Thursday night for folk icon Arlo Guthrie.

More than 2,500 people filled the area next to the Sea Dog Restaurant for the five-hour event that included artisans, vendors, union members and political activists. The concert itself started at 7 p.m. and ended a little before 10 p.m.

Guthrie filled in for the 82-year-old Pete Seeger, who was too ill to travel from his home in New York’s Hudson River Valley, to perform in a “Concert for Our Future,” a benefit for Peace through Interamerican Community Action. After Seeger bowed out, the program, which included the singer’s performing partner Linda Richards in addition to Guthrie, was dubbed “A Tribute to Pete Seeger.”

A hush fell over the crowd when a tape of Seeger’s voice was played. He apologized for not being able to attend and introduced Guthrie, whose father Woody Guthrie played with Seeger in the 1940s.

“You’re in luck,” said Seeger, his voice showing its age. “Arlo can make it. Perhaps, I’ll make it some other year.”

Guthrie’s relaxed style and humorous stories charmed the large crowd that included senior citizens, baby boomers, teen-agers and babies. Accompanied by his son Abe on keyboards, Guthrie opened with “The Chilling of the Evening,” closed with his father’s most famous song “This Land is Your Land,” and came back for an encore of “City of New Orleans” as a train crept past the concert site.

He even led the crowd in the Elvis Presley hit “I Can’t Help Falling in Love With You.” Guthrie also recited a poem he wrote about a moose. Last year, Alice Brock, the Alice from Guthrie’s 1969 hit “Alice’s Restaurant,” illustrated the poem for a book. Guthrie does not perform that 181/2 minute song any more, even though audience members shouted for him to sing it Thursday night.

Ramblin’ Jack Elliot, another of Woody Guthrie’s friends and colleagues, joined Arlo Guthrie for a couple of songs. Audience members familiar with the ’50s folk scene gasped and applauded when he sauntered onstage in his big, black cowboy hat. Others whispered to each other, asking, “Who is this guy?”

It was the Peruvian band Inca Son that had concertgoers dancing in the aisles, however. The combination of percussion, strings and flutes was hypnotic, and even those who chose not to dance could not keep their feet still as the group performed wearing native clothing from the Andes Mountains.

Members of the group surprised Guthrie when they led the audience in a chorus of “Happy Birthday.” Guthrie turned 55 Wednesday, July 10. While he may not have been surrounded by old friends, he was serenaded by fans of all ages under the stars on a near-perfect Maine summer evening.

Pete Seeger would’ve loved it.