A few years ago, I was in the audience for a live radio show, when the renowned American country singer Glen Campbell took to the stage. What the listeners of the programme could not have seen was his obvious confusion about where he was and what was going on, nor the gentle supportive guidance from his daughter, a fellow musician on stage. And yet as soon as he struck the opening chords for his first number, the singer came to life. He didn’t miss a beat as he gave a faultless and animated performance of one of his big hits. Just one year later, his family announced his diagnosis of Alzheimer’s disease.

This devastating condition is something that Campbell has in common with Ted McDermott, a 79-year-old man who made headlines this month after YouTube footage of him singing in his car with his son went viral. Despite the fact that Ted sometimes struggles to recognise even his closest family members, he can still remember all the words of his favourite songs. What makes the video so moving is the incredible sense of connectedness and warmth between Ted and his son as they sing together.

So why is it that these two men, stripped of so many of their memories, are still happy and able to sing the songs they love? Could music provide an important channel of communication when so many other abilities are failing? The surprising thing about music is that, contrary to popular belief, we don’t actually learn songs particularly easily. However, once those memories are formed, they become exceptionally robust and easily accessible. This is brilliantly illustrated in a elegant study by Carol Krumhansl and colleagues from Cornell University. They found that most people can recognise popular songs, such as Hey Jude by The Beatles and Thriller by Michael Jackson, after hearing just half a second of the track.

There have been a number of detailed case studies published that offer support for this hunch that musical memory might be disproportionately preserved in dementia. And last year an exciting study shed light on why this might be so. Jorn-Henrick Jacobsen and his colleagues found that memories of old songs activate very specific areas of the brain: the caudal anterior cingulate and the ventral pre-supplementary motor area. Crucially they also found that these same areas seem to be particularly resistant to the damaging effects of Alzheimer’s disease.

The notion that people with dementia may benefit from singing and other musical activities has grown increasingly popular in recent years, with initiatives such as Singing for the Brain being offered by the Alzheimer’s Society, and the emergence of charities like Lost Chord who take professional musicians into care homes. Labour MP Dennis Skinner is a firm supporter. He found that singing with his mum became a crucial part of his relationship with her as dementia took hold. He now regularly sings with residents at his local care home.

Tapping into autobiographical memory

So music seems to be robust and to withstand the effects of neurodegenerative decline and other acquired brain injuries, but why is it such a valuable activity for these people? One key finding is that music is a particularly good cue for autobiographical memories – these are memories that reinforce our sense of identity and play a hugely significant role in how we connect socially and emotionally with those that are close to us. Tunes that we first encountered between early adolescence and our late 20s seem to be particularly evocative.

At an even more fundamental level, scientists such as Jaak Pankseep have argued that music is a core ingredient of emotional communication. After all, much of our interaction with pre-linguistic infants depends primarily on changes in voice tone, and most parents would agree that it is the most natural thing in the world to soothe a baby with a lullaby. Music also contributes to spoken language; without the melodic nuances, our words would sound robotic and devoid of any feeling. And what are screaming, laughing and crying if not distinctive changes in pitch, rhythm and volume? These essential communicative qualities of music must in part be why singing provides such a sure way to connect with people who have severe cognitive impairments.

But music is more than just a fun activity that connects people, there is good evidence that it can significantly improve objective measures of health and well-being. Apart from the likely physical benefits of singing as a cardiovascular activity, musical engagement may also reduce levels of the stress hormone cortisol, increase immunity, lower perception of pain and reduce symptoms of depression. Most importantly, for families such as those of Ted McDermott and Glen Campbell, music has been shown to improve the mood, memory and overall quality of life in people with dementia. Those of us who live or work with dementia can learn from their example. All the evidence suggests that music may offer a unique and important way to communicate when all other roads are closed.