A 17-year-old from the southwestern Ontario town of Essex was invited onstage to play guitar with the Foo Fighters during a concert in Cleveland.

“It was interesting having 20,000 people scream at you,” Lucas Gregetz told CTV Windsor. “It was really cool.”

Gregetz travelled with his dad to the American city on July 25 to catch the alternative rock legends -- his third time seeing the band. Standing in the front row during the show, he hoisted up a handmade sign that read, “Let me jam Monkey Wrench please.”

Foo Fighters frontman Dave Grohl took notice.

“I had the sign and he was looking at me, he eyed me for a bit,” Gregetz recalled. “I’m like, ‘Dude, I’m coming up, I’m doing it!’ He’s like, ‘All right, get up here.’”

Gregetz didn’t want to waste any time.

“I know when he brings people up, he tries to chat with them,” Gregetz said of Grohl. “But I knew I’d start getting freaked out standing there waiting to play the song, not wanting to screw up, so was like, ‘Ok, I'm ready.’”

Handed a guitar, Gregetz immediately started strumming the chords of his favourite song: the band’s 1997 hit “Monkey Wrench,” which was released years before Gregetz was even born.

“Lucas brought his own f---ing guitar pick with him!” Grohl exclaimed from the stage. “He knows it!”

For seven minutes, Gregetz played like a pro.

“I went around to each band member and played with them for a little bit,” the teenager said of his performance. “I wanted to go around and kind of thank everyone, I guess, for letting me jam.”

Filming it all was his dad.

“It was crazy,” Steve Gregetz told CTV Windsor. “He looked pretty comfortable up there, having a good time.”

With a report from CTV Windsor