Young Cancer Patient Sings 'Fight Song' with Rachel Platten

Since being diagnosed with a rare form of cancer in May, 7-year-old Jeremiah Succar has had one tune stuck in his head – Rachel Platten's Fight Song.

Recently, the singer surprised the little boy at Children's Hospital Los Angeles after learning through social media about him.

During her visit at the hospital, Jeremiah and Platten sang a flawless duet of his anthem while hanging out in his room.

WATCH: 6-Year-Old Boy with Cancer Dances with His NFL Idols

"Jeremiah loves Fight Song," his dad Jerry Succar tells the hospital. "He memorised the lyrics after three or four times listening to it. 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."

According to the hospital, Jeremiah was diagnosed with stage-four atypical rhabdoid teratoid, "an aggressive, fast-growing tumour that occurs in the brain and spinal cord," and just finished his second round of chemotherapy.

After wrapping up the song, Jeremiah had just one question for Platten: "Can I have your autograph?"