Before documentary filmmaker Michael Rossato-Bennett began shooting “Alive Inside,” a powerful documentary about music’s impact on Alzheimer’s disease, he admits that he went into it with the common misconceptions that many of us have about the disease.

“I went into these nursing homes, and I think I was like most people in that I saw these people who have no memory and very little functioning, and I intuitively thought they were gone; that there was nothing there,” he says. “The mysteriousness for me was the continual opening of my understanding of what was still there.”

Rossato-Bennett directed the film, which quickly triggered a cultural ripple effect. After winning the Audience Award at the 2014 Sundance Film Festival, it soon sparked a word-of-mouth buzz that spread like Internet wildfire.

The film shows exactly what happened when people suffering from dementia – people who were seemingly “gone,” as Rossato-Bennett described – heard music from their youth. 

The reactions were unlike anything the filmmaker ever expected.

“I filmed an old man who had been sitting slumped over for 10 years,” he says. “We gave him his music, and he woke up with such profoundness on every level that it rocked me to my bone.”

What’s more is that not only did these folks respond and light up; many of them also began recalling lost memories that appeared to be unearthed by the music. Some who’d been unresponsive to medications even regained motor skills.

“It really profoundly changed the way I listen to music,” says Rossato-Bennett, adding that the documentary may very well be the only good-news film ever made about Alzheimer’s. “Some of these people would hug me, and I could feel this incredible aliveness in their emotional state; kind of this slow dawning that the emotional side of these people’s minds was actually perfectly functioning.”

He was so moved by the experience that he created the Alive Inside Foundation. The organization is designed to inspire young people to connect with their elders. According to Rossato-Bennett, music is a universal language capable of bridging the generational gap.

“This is the humblest of human situations; to be dealing with the diminishment of all that makes you who you are,” he says. “But certainly there’s a silver lining in the fact that we can make people in nursing homes' lives better, or we can make the elders in our lives better, or we can make ourselves better by connecting through music and stories. It is not time wasted.”

Click here to watch the trailer for "Alive Inside."