A music therapist in Houston sings "Happy Birthday" and stops just short of the last word. Her patient sings it. The patient was Gabrielle Giffords, a congresswoman from Arizona. She had been shot in the head in 2011, and the wound had taken away her ability to talk. Her music therapy began with songs like that one.
Over time she learned to say ordinary phrases in a sing-song voice. Songs gave way to chants, and chants to spoken phrases with the rhythm of speech. In November 2011, ABC News aired footage of her therapy. It shows her crying with frustration when she tries to talk and can't. It also shows her singing fluently, and looking joyful. ABC reported that she had relearned how to talk, and gave music therapy part of the credit.
Her story suggests that a song can carry words past damage that blocks speech. Can music help a damaged brain? And if it can, which part of the music does the helping, and how much? The last lecture found music lessons doing best on skills that share music's machinery, like hearing the separate sounds inside words. The fifth lecture found another piece of that machinery: your brain keeps a beat with its movement system, the parts that plan and time movement.
We'll come back to Giffords at the end. Music's help is clearest in walking, so we'll start there and judge her story against it. In trials, people with Parkinson's disease who trained with a beat walked a little better, on average. In trials after a stroke, too, walking to a beat sped people up a little, on average. Then we'll follow the beat from the feet to the mouth, into singing therapies like hers, and ask which part of a song carries the words. The last part is about why a story like hers comes out bigger than the trials. One thing should be clear from the start. Everything here comes from studies of patients, and none of it is a treatment plan for anyone.
In Parkinson's disease, walking can stall. A person means to walk, and for a moment the feet stop going forward. That's called freezing. Somewhere between twenty-five and sixty percent of people with Parkinson's have it, usually after some years of the disease.
Oliver Sacks described an extreme case of freezing. Sacks was the neurologist and writer who visited Clive Wearing, the musician whose memory lasted only seconds, in the sixth lecture. His patient Edith T. had been a music teacher. She didn't have ordinary Parkinson's disease. She was one of the patients in his book Awakenings, all survivors of the encephalitis lethargica epidemic. It had left them with an extremely severe form of parkinsonism.
She told Sacks that her movements had become "wooden, mechanical." In her own word, she had been "unmusicked" by the illness. Often she froze, utterly still, "like a still photo, a frozen frame," until music came to her. The music played in her head, not in the room. She called it "catchy tunes, rhythmic tunes, the sort I loved to dance to." Then she could move again, freely. In Sacks's telling, a companion could do the same. With someone walking beside her, she walked perfectly. The moment they stopped, she stopped too.
That's one writer's account of one extreme case, and it isn't a technique. What it shows is a pattern. A body that can't set itself going can still be set going by a rhythm, even one in the head, or by a person walking alongside.
The fifth lecture found two parts of the movement system working harder for a beat: the basal ganglia, the deep timing machinery, and the supplementary motor area, a planning area. Parkinson's damages the basal ganglia, and people with Parkinson's are worse at telling apart rhythms with a beat.
An outside signal that helps a person start a step and keep going is called a cue. A 2018 review of walking to a beat in Parkinson's describes those two areas as the brain's own, inner cueing system. In Parkinson's, that inner cue, the brain's own clock for movement, works poorly. Steps get shorter, and walking slows.
Why would a beat help, then, if the disease damages the machinery that keeps one? The music researcher Michael Thaut began studying walking to a beat in the early 1990s. On his account, a steady beat from outside gives the brain a second clock. I'd add that the brain doesn't have to keep that clock running. A metronome marks every beat by itself. Thaut argues that the steady gap between beats tells the brain how long each step should take. So at any point in a step, the brain knows how much time is left, and it can plan the movement to fit.
Thaut's is one account among several. The 2018 review lists others, and says the benefit may have several causes. It also guesses that movements cued from outside may take another pathway around the damaged circuit, and it presents that as speculation. Nobody yet knows how the outside clock gets to the legs.
How much does it help? The clearest single test here is a trial in three European cities that took 153 people with Parkinson's. A lottery decided who trained first and who waited. A therapist came to each patient's home nine times over three weeks. Each patient wore a device built for the trial. It could give a beep in an earpiece, a flashing light on a pair of glasses, or a pulsing buzz under a wristband. Patients tried all three and trained with the one they liked. Two-thirds chose the beep, and a third the buzz. Almost no one chose the light. They practiced landing each heel on the rhythm. Their usual medicines carried on unchanged. Then testers measured them at home, without the device. The testers were never told which group a patient was in.
On average, the patients walked five centimeters a second faster after the training, with steps four centimeters longer. Their balance improved, and freezing eased a little in those who froze at least once a week. They felt more confident about everyday activities, but the activities themselves and their quality of life didn't change. The gains were there when the training ended, and had shrunk considerably six weeks later. The authors call the benefit "small and specific." They couldn't rule out that some of it came from a therapist's attention. Still, they conclude that cueing training may be a useful addition to the treatment of walking problems in Parkinson's.
A 2018 review of fifty studies found the same pattern. Forty-six of them reported gains, but the gains came mainly where people trained with a beat for weeks, not where they simply walked to one. A later review that kept only trials with a lottery found strides about five centimeters longer. A beat from outside, it seems, can do some of the timing that the brain's own clock has lost. With weeks of practice, it buys a few centimeters of stride, on average.
After a stroke, walking is often slow, lopsided and tiring. A team from several American centers tested a system that turns pop music into a walking coach. Each walker wore a headset and a sensor on each shoe. The songs came from many styles, rock and roll, pop and disco among them, each picked for a strong beat. The system set the tempo to the walker's own pace. It nudged the tempo up only while the walker kept in step and walked evenly. Steps that drifted off the beat brought in a louder rhythm track.
A lottery split the patients into two groups. One walked with the system for half an hour, three times a week for five weeks. The other did the same walking without it. The patients were about eight years past their strokes, on average, and all of them already walked without help.
Over the five weeks, the music walkers sped up by fourteen centimeters a second, on average. The others sped up by six. The trial's own bar for a gain that matters clinically was sixteen centimeters a second. The music group's average fell short of it. Still, four in ten of the music walkers cleared it, against one in eight of the others. The company that makes the system paid for the trial, and several authors work for it or advise it. Everyone knew who had the music, and nobody was tested again afterwards.
A 2017 review of music after brain injury pooled nine trials of walking to a beat after stroke. After training, the people who walked to a beat were faster than the comparison groups by about nineteen centimeters a second, on average. In the walking-coach trial, that gap was about eight. But the reviewers rated the evidence on speed as moderate in quality, and they judged nearly all the trials in their review at high risk of bias.
Does the music matter for walking, or only the beat? No trial in this lecture set the two against each other directly. The 2017 review compared trials that used music with trials that used a bare beat, like a metronome's. In walking speed, trials that used music showed a gap over the comparison groups nearly twice as large. The reviewers say only that music may work better, and call for trials that set the two against each other. They note that music can motivate exercise. For walking, the beat is the part known to help, and the music may add something on top.
Walking is where the evidence is clearest. On average, in trials, a steady beat helps people with Parkinson's or after a stroke walk a little better while they train. Words are a stiffer test. Talking is movement too, and the mouth, the breath and the voice have to work together. Can a beat time that?
The second lecture met people with aphasia, a loss of language after brain damage. Some could no longer talk, and yet could sing a familiar tune. In the reading of Isabelle Peretz, the Montreal psychologist from that lecture, the words usually fail, sung or spoken. But some patients have been reported singing words too. In 1973 that observation became a treatment, first described in three patients. It's called melodic intonation therapy.
A patient sings short, everyday phrases on just two notes. The higher note goes on the syllables that speech would stress. The patient taps each syllable with the left hand, at about one syllable a second. Sessions are one-on-one with a therapist, who starts with a word like water and works up to asking for a cup of coffee. The therapy's inventors thought singing would bring in undamaged areas on the brain's right side, to make up for damaged language areas on the left. Its supporters wrote in 2008 that this hadn't been proven.
Gottfried Schlaug was a neurologist at Harvard Medical School. In 2008 his team compared the therapy with plain spoken practice in two men who could say very little after a stroke. Each spent an hour and a half a day, five days a week, with the same therapist. One sang and tapped. The other spoke the same phrases and didn't tap. Both improved, and the man who sang improved more. Schlaug's team suggested that the tapping might pace speech the way a metronome paces other movements. But the comparison took away the tune and the tapping at once, so it couldn't say which mattered.
Benjamin Stahl and his colleagues in Leipzig tested the tune against the rhythm. They worked with seventeen stroke patients in Berlin who understood much of what they heard and could say little. Each patient sang or spoke along with a recorded voice, over a wooden click. In one condition they sang. In another, they spoke the same words to the beat. In a third, the click switched to a waltz's grouping of three and slipped half a beat off the voice, so it no longer kept time with the words. Every syllable lasted just as long in all three. Tapping wasn't allowed. Some of the words came from a well-known German nursery rhyme. Some were everyday stock phrases, and some were strange, poetic lines that nobody would say.
Which did more for the words, the tune or the beat? In that test, singing added nothing. The patients got a little over half their syllables right whether they sang or spoke to the beat. The mismatched click did cost syllables, and the cost fell on the nine patients with more damage in the deep timing machinery. In the eight with less damage there, it made no such difference. The words mattered too. In every single patient, the stock phrases came out better than the strange lines. The team titled its paper "Rhythm in disguise." It suggests that benefits long credited to singing may have their roots in rhythm.
That was one round of testing, with seventeen people. It measured what they could say then, not what months of therapy can do, and it doesn't show the therapy is useless. It leaves two of the therapy's ingredients standing: well-practiced phrases and a beat. What it questions is the tune. One earlier study had found that singing along did help. Stahl's team notes that singing slowed the syllables down in that study, and slower syllables may have done the work.
Here the feet and the mouth meet. The deep timing machinery turned up in both. In Parkinson's, its damage is thought to be part of why walking can lean on a beat from outside. In Stahl's patients, those with damage there seemed to lean on one for speaking. I'm the one drawing that link. The two illnesses damage that machinery in different ways, and Stahl's result rests on seventeen people tested once. But the link suggests the beat does one job in both places. It times a movement the brain can no longer time well.
What happened to Giffords isn't a study of this therapy, but it works the way a case report does. That's an account of one patient, or a few, treated and watched, with nobody untreated to compare. A 2022 review from Vienna and Berlin set the singing therapy's case reports against its trials. Stahl was one of its authors. Of its twenty-two studies, only three were trials that used a lottery. On the same kind of test, the case reports found gains 5.7 times as large as the trials did.
In the trials, the gain was small to moderate, uncertain enough to include zero, and mostly in repeating phrases. For everyday communication, this one technique's trials showed negligible progress, though only two small trials measured it. The same review notes that other speech therapy methods, used together, have shown moderate gains in communication in large trials.
Why would the case reports run so large? Their gains were biggest in patients treated soon after a stroke, and smaller the longer the wait. The authors point to recovery that comes on its own. In the months after a stroke, a brain gets back some language with or without therapy. Researchers call that spontaneous recovery. A case report counts it as the therapy's. That leaves a case report unable to measure the therapy. It doesn't make therapy pointless.
A therapist's attention is a second worry. The Parkinson's trial couldn't rule it out, and a case report can't separate it from the therapy either. The review's authors still see a use for the singing therapy. They write that for someone with severe aphasia, a set of trained phrases for everyday needs may bring a substantial gain in quality of life.
And Giffords? One recovery has nothing to measure itself against, so nobody can say how much of hers the music did. Her therapist thought that her love of music may have helped her through the hard work. In 2021 Giffords gave PBS an interview she had prepared for over several weeks with her speech pathologist. In it she said: "The words are there in my brain. I just can't get them out."
So music can help a damaged brain, a little, mostly through its beat, and mostly while people practice. For walking, the trials point the same way, and the gains are counted in centimeters. For words, the tune mattered less than its champions thought, at least in one careful test. Rhythm and well-worn phrases seem to carry more. And a single story runs ahead of the trials, because it can't tell the therapy from the recovery a brain makes on its own.
How long the gains last is still open. The trials here either didn't look, or found the gains shrinking within weeks. So is the question of how much music adds to a bare beat. These are research results, not advice for any one person. For that, the people to ask are a person's own physical therapist or speech therapist.
For most of this course, your brain has been the one making the music. It builds a pitch from a stack of harmonics, bets on the next note and helps supply the beat. Here a damaged brain borrows its beat instead. In the largest trial in this lecture, nobody played any music at all. The patients trained to a beep, and a third of them preferred a buzz on the wrist. What helped them, a little, was the beat.