Rachel Platten Sings 'Fight Song' with Young Cancer Patient

— -- In an inspiring video shared on Facebook today by the Children's Hospital Los Angeles, singer Rachel Platten stopped by to cheer up a young cancer patient and ended up signing a duet with a brave young boy.

Jeremiah Succar, 7, loves Platten's hit "Fight Song" and after a "#RachelMeetJeremiah on Instagram" campaign, the hashtag reached the singer, so she came for a visit on Tuesday.

"This video says it all," the hospital wrote on its Facebook page. "CHLA patient, Jeremiah, has a lot of heart and a lot of fight—thanks in part to his #FightSong! He surprised singer/songwriter Rachel Platten by knowing the lyrics to her hit single by heart. #ccam."

Jeremiah knows the lyrics and does his best to do the song justice, which is exactly what he does. You can see Platten start to break down herself witnessing the boy's amazing spirit.

"You are so amazing!" she says, after they finish singing.

Jeremiah was diagnosed with Stage 4 atypical rhabdoid teratoid, "an aggressive, fast-growing tumor that occurs in the brain and spinal cord," the hospital's blog explains, adding he just finished his second round of chemotherapy.

“Jeremiah loves 'Fight Song' — he memorized the lyrics after three or four times of listening to it,” Jeremiah's father Jerry told the hospital blog. “He used to sing it when he got a lot of headaches, but now he sings it in the morning, before bed and during shots he has to get.”

In hundreds of comments, supporters say the video brought tears to their eyes.

"This is amazing. I'm crying and smiling together," wrote one poster. "What a beautiful moment."