High school choir teacher Gabrielyn Watson has touched many lives - so her former students decided to let her know just how much she is loved.

After hearing that she was going through a rough patch with her health, the group returned to Morgan Park High School in Chicago, Illinois to surprise her and express their gratitude.

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"I realized that I never really had a chance to let her know just how influential she was in my life," said one student, Peter Frank, who was a finalist on Season 10 of "American Idol."

As a video shared by Kleenex shows, Ms. Watson was shocked - and immediately tearful - when Peter jumped out in the school's hallway and began singing "Amazing Grace."

When other students filled the hallway and joined in with the performance, the teacher dropped to the floor, sobbing.

"It's just great to feel loved and that what you do matters," she said in the video. "I love my students and I want them to have the best opportunities so that they can thrive."

Ms. Watson, 59, has been a teacher for nearly 17 years, although she took off seven months to fight multiple myeloma. She is now in complete remission.

Frank, who graduated from the school in 2005, said he credits Ms. Watson with his success as an entertainer in Los Angeles. He recalled how she once gave him a tux for a chorus competition because he could not afford one.

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Frank contacted Kleenex to help with the surprise, calling Ms. Watson an "unsung hero who deserves recognition."

"Because of you, I'm everything I am today," he tells her in the video, wiping away his own tears.

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