It won't cure dementia or Alzheimer's disease, but music can nevertheless help sufferers "wake up" their memories, reveals a moving documentary presented at the Sundance Film Festival.
"Alive Inside: A Story of Music & Memory," the debut feature film by Michael Rossato-Bennett, follows the efforts of one man to convince Americans of the benefits of music on people with dementia or Alzheimer's.
Dan Cohen, founder of the non-profit organization Memory & Music, arms himself with headphones and music players as he shows -- to the surprise of care-givers -- how patients locked in silence and lost in the maze of dementia seem to find some memories and feelings when they hear the music they love.
With the cameras watching on, many patients begin to talk, smile, sing and even dance, as their families look on stunned.
"It's not a cure," stressed Rossato-Bennett, whose film went on show at the independent film festival in Utah, the United States, at the weekend.
"And there is no way to get (back) these memory cells that have been destroyed."
But he says music has the ability to penetrate into the recesses of the brain less affected by dementia, which affects five million Americans.
Cohen's vision when he founded Memory & Music was a simple one: to bring a better quality of life to the elderly through music.
The fate of the elderly and infirm is one Rossato-Bennett shows an intense passion for.
"We live in a time, in a culture, where we're not really sure how much we care about humanity anymore," he told AFP at Sundance, which runs until January 26 in Park City.
"We know we care about industry, progress, commerce. But maybe elders are no longer useful. We're done with them."
He added: "Humanity is at a turning point. With our technology, we're gods.
"I really think we need to rethink almost everything and we'll have to, eventually. If we are creating global warming, at some point, we can't ignore it. If we are overfishing our oceans, at some point we can't ignore it.
"If our elders are not having a human life, at some point we cannot ignore it. So we will change.
"In 10-15 years in the US, we're gonna need to double the beds in nursing homes if we do it that way. We can't do it. We can barely afford what we have now. Double would literally bankrupt this country. People are gonna have to live at home longer, that's the only solution.
"When you have Alzheimer's or dementia, the world becomes overwhelming, you can't differentiate what's happening outside and inside, you can't do it."