Alive Inside, a documentary film being shown in selected theaters across the U.S., tells the story of a social worker using iPods and personalized playlists to bring new life to nursing home residents with Alzheimer’s.

Dan Cohen puts together playlists of music from when the patients were young, transfers them to an iPod and then plays them to patients who had been unresponsive to conversation, generating dramatic transformations, reports Re/code.

Audiences first encounter Henry hunched over in his wheelchair, head down, hands clasped firmly together, unresponsive to the world around him.

As soon as a pair of headphones are placed on his head, the 94-year-old dementia patient opens his eyes, sits up straight and begins swaying and humming along with the music. Henry speaks animatedly about his favorite band leader, Cab Calloway, and even begins to emulate the jazz artist’s style of scat singing — at one point launching into a rendition of “I’ll Be Home for Christmas.”

Cohen discovered that music tapped into parts of the brain that could not be reached in other ways, and could revitalize people even in late-stage dementia, “demonstrating music’s ability to combat memory loss and restore a deep sense of self to those suffering from it.”

Described as “a joyous cinematic exploration of music’s capacity to reawaken our souls and uncover the deepest parts of our humanity,” Alive Inside won the Audience Award at the 2014 Sundance Film Festival. Apple is reportedly helping to promote the film, and a list of theaters where the film can be seen is available here.