Entertainment Tonight ET Online ETOnline.com

Even while in remission of multiple sclerosis, Donny and Marie Osmond’s nephew David continues to find new challenges for himself. The latest test? Covering an Oscar-winning duet.

VIDEO: David Osmond's Uplifting Katy Perry Cover

In a moving, new music video, David and Jessie Funk belt out Falling Slowly from the 2006 film Once. The duet, originally performed by Glen Hansard and Marketa Irglova, won the Academy Award for Best Original Song.

Growing up in a musical family, David has been performing since the age of 4. In 2009, he auditioned for American Idol where he revealed to Ryan Seacrest that he had been diagnosed with MS. The disease sometimes leaves him unable to sing and has even confined him to a wheelchair for extended periods of time.

"It's like a roller coaster," he said of the disease. "It has a remittance and a relapse. It's very likely that MS ... could flare up, and I could go back to that wheelchair."

Watch the video to see David’s inspiring example as he shows off both his incredible voice and courage. The clip also features composer Nathaniel Drew and the Salt Lake Pops Orchestra.