Top 8 contestant John Foster performs on Season 23 of “American Idol.” (Disney/Eric McCandless)Disney

In April, “American Idol” hopeful John Foster advanced from the Top 20 to the Top 14 with a performance of his tearjerking original song “Tell That Angel I Love Her.” The 18-year-old Louisiana singer penned the tune about his late friend, Maggie Dunn, who died during his junior year of high school.

As it turns out, that angel had a message for Foster, too. During Sunday night’s Season 23 finale, “Idol” viewers got to learn more about Dunn through a segment that showed Foster returning to his hometown of Addis, Louisiana and visiting his friend’s grave.

In the clip, Foster called Dunn “instrumental” in his life, noting that “when I lost her, it was just like a whole part of me had been torn out.”

Foster also shared that Dunn had written him an encouraging letter a few months prior to her death in December of 2022.

“You are so talented,” Dunn wrote. “You have such an amazing voice, and you should let everyone hear it.”

“Believe you can, and you’re halfway there,” the letter concluded. “Your voice is too good to go unheard.

Looking back on Dunn’s note, Foster linked her motivational words to his success as an “American Idol” finalist.

“If it wouldn’t have been for her, I don’t know if I ever would have been in the position that I am today,” he said.

The segment also showed Foster tearing up as he performed “Tell That Angel I Love Her” for his hometown fans.

Foster was one of three remaining “Idol” contestants in Season 23; the end of Sunday night’s season finale revealed Jamal Roberts as this season’s winner.