PORTLAND — When Deering High School music teacher Gilbert Peltola told members of his chorus they’d been chosen to perform alongside one of the top-selling rock bands of all time, they had a variety of reactions.

“I don’t think anybody really believed it at first,” said Olivia Ryan, a junior at the Portland school. “We were just like, ‘Oh, Mr. Peltola is joking with us.’”

But as all 26 of the chorus members were born nearly two decades after the band Foreigner released its first album, in 1977, some admitted being a little lost by the announcement.

“I didn’t know the band,” admitted junior Kerry Sullivan.

Now, though, Sullivan said the anthemic 1985 smash hit “I Want to Know What Love Is” — which the Deering chorus will be singing Feb. 18 on The State Theatre stage with Foreigner — is “stuck in my head every day.”

“It’s really catchy,” she said.

“They were excited,” recalled Peltola of the moment he told his singers about the opportunity. “Their parents were even more excited.”

Foreigner has 10 multi-platinum albums and has sold more than 80 million records worldwide. Last year, two of its founding members, Lou Gramm and Mick Jones, were inducted into the Songwriters Hall of Fame.

“I’m more of a jazz person … but if you listen to the radio, you’ve listened to Foreigner,” Peltola said. “I know all of their songs.”

The music teacher said he believes the Deering chorus just got lucky in terms of why it was offered the on-stage honor.

“I think (Foreigner) had a list of choruses, they called us first, and I said, ‘yes,’” Peltola recalled. “That was the end of that.”

The chorus members made black-and-purple T-shirts in honor of the event and have been rehearsing “I Want to Know What Love Is” in preparation for the concert next Tuesday.

Chorus members also will help raise money for the Grammy Foundation by selling Foreigner CDs before and after the show, according to a Portland Public Schools announcement. The foundation helps support music education in high schools nationwide.

Foreigner, which previously invited the Greater Bangor New Renaissance Singers choral group to help out during a Rockport concert last summer, will also donate $500 to the Deering chorus.

“It was really exciting to hear about getting that $500,” sophomore Sophia Morin said. “We know the budget is really tight here.”

Ryan agreed: “We know how hard it is in the district right now, and when they’re looking at (spending) cuts, they’ll see, ‘Hey, the music department is really doing great things.’”

Most of the chorus members agreed that, despite the profile of their new on-stage partners, they’re not nervous about the upcoming show.

“(The audience is) going to be focused on Foreigner,” Sullivan said.

“It’s not like we’ll be singing the song and Foreigner is backing us up,” agreed Ryan.

Either way, it’ll be memorable, said Peltola.

“You don’t get to be on stage with a world-famous rock band of any kind very often,” he said. “I hope this is something they carry with them throughout their lives.”