This Friday, a choir thousands of singers strong will perform Zach Sobiech's "Clouds" at the Mall of America for the fourth consecutive year. The performance is intended to honor Sobiech and other young victims of cancer.

"If someone were to tell Zach four years ago that the song he had chicken-scratched into his notebook would be sung by thousands of people as an anthem of hope four years down the road," wrote Sobiech's friend Sammy Brown in an e-mail, "I think he'd smirk and say something like, 'Okay, good one.'"

The "'Clouds' Choir for a Cause" concert, which will include performances of "Clouds" and a host of Christmas carols, will begin at 6:30 p.m. Sobiech's impact on others has been strong since his death in May 2013 at age 18 from osteosarcoma. A video of “Clouds” has accumulated nearly 13 million views on YouTube, and the song hit No. 1 on the iTunes chart. "Clouds" has also helped raise over $1.3 million for the Zach Sobiech Osteosarcoma Fund, which donates proceeds to the Children's Cancer Research Fund.

"The fact that this event has only grown in attendees is incredible," wrote Brown, who was a classmate and songwriting partner of Sobeich's. "When you lose someone, I think there's this fear of forgetting, or that the rest of the world will forget. In Zach's case, more and more people are remembering."

Brown will be in attendance on Friday as well, performing an original song about remembering her friendship with Sobiech. Three years after the first concert, Brown is thankful. "Zach has established a sense of immortality through the legacy he's left and the people he has impacted. I'm thankful for the opportunity to somehow create more memories with him."

Ibad Jafri studies International Relations and Cinema & Media Studies at Carleton College.