“Alive Inside” opens Friday at Sundance Cinemas. Not rated, 1:14, three stars out of four.

“We are made to age,” filmmaker Michael Rossato-Bennett says about halfway through “Alive Inside,” which may be the most radical statement you’ll hear in a movie theater all year. As Rossato-Bennett correctly points out, modern American culture thinks of adulthood as the apogee of the human condition, while growing old is considered nothing more than an inexorable deterioration of that perfect state.

“Alive Inside” is a deeply moving film that uses a relatively modest idea — that even the most catatonic and demented of elderly patients might be reachable through music — and sets it pretty effectively against this larger mission statement. While it may be easy to say that person is “gone” mentally and emotionally, and merely medicate them comfortably through their final years, the fact that their minds and hearts may be reachable puts a moral imperative on the rest of us to do so.

The Music + Memory Project started by social worker Dan Cohen seems almost too simple — give seniors suffering from memory loss an iPod packed with favorite songs from their younger years. The transformations we witness are remarkable — whether it’s a bipolar woman calmed by opera, or seeing a nearly incoherent man’s eyes light up at the sound of Louis Armstrong and start singing along, there’s something about music that can find “a back door to the mind,” as Cohen puts it. Rossato-Bennett interviews author Oliver Sacks (who wrote a fascinating book on the subject, “Musicophilia”) and musician Bobby McFerrin on how the brain seems to have an innate response to music.

And a very personal response, as hearing “their music” brings back these individuals’ sense of self, including memories thought long buried. (It’s fitting that the folder on your laptop is labeled “My Music.”) But live musical performance also has a similar balm — one of the most fascinating subjects is a volunteer who plays music at a nursing home — he’s from Africa, and draws the connection between music’s power to soothe souls in his war-torn homeland and its effect on the senior citizens it works with.

Much of the film follows Cohen’s attempts to get funding for Music + Memory, which isn’t quite as compelling as the character studies of the patients. (There’s also a weird meta-moment where we see a CNN piece on the movie in the movie.) But this is a thoughtful and compassionate film and, if you have a loved one in your life with Alzheimer’s Disease or similar syndrome, you’re probably already on your way to the Apple Store.