Music can summon old memories in Alzheimer’s patients. But they aren’t always happy ones.

Music flowed from Marian like a waterfall. She sang all day, every day. The people around her couldn't stand it.

To the nurses and to the other residents of the unit, Marian's singing sounded like shouting, a frequent reality among people who have Alzheimer's-type dementia. When I went to pick her up for our first music therapy session together, I had been given some idea of what to expect, but I didn't anticipate the nastiness. Half a dozen older women sat in wheelchairs lined up in front of the nurse's station. Marian, on the far left, was belting at full volume. One of the others shouted back, "Shut up!"

I'm sure the nurses were hoping I'd return Marian in a calmer state. Traditionally, the goal of music therapy for people with dementia is to reduce agitation. But I soon realized my job wasn't to stop the shouting — just the opposite. Music offered unique access to Marian's self, long after disease had dismantled her personality.

The music of Marian's childhood is synonymous with shouting. "Field hollers" is the term folklorists use to describe the blues-inflected call-and-response patterns carried down for centuries, first by slaves and then by sharecroppers in the rural Deep South of the 1930s, where Marian grew up. She sang extended improvisations on spirituals, constantly recombining them with melodies of her own invention.

This was the music of the world her mind had returned to, an often unhappy time. The violence and abuse of antebellum plantation life remained part of the rural black experience well into the Jim Crow era, and as a child Marian was beaten and whipped regularly by her father. She ran away from home, married, left her husband, married a second time, and fled from him, too. Marian could no longer remember her daughter, but her daughter described Marian like this: "She's a runner."

Listening to familiar songs can trigger memories. But the emotions churned up by these memories can be quite painful, carrying with them the aftershocks of trauma. Music therapists know there is never a guarantee that music will unleash a happy reminiscence.

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In recent years, the internet embraced footage of an older man named Henry. When we first see him, Alzheimer's has shut him down. But given an iPod loaded with the music of his youth, he quickly comes to life.

The virality of Henry's transformation draws public attention to music's special gift. New research suggests long-term musical memory is stored in a part of the brain that deteriorates only in the late stages of Alzheimer's. But the video leaves viewers with the mistaken belief that handing someone an iPod qualifies as music therapy, a profession whose practitioners receive certification from a national board after years of training. An iPod might well trigger memories — but they won't always be happy ones. You can bring the past back to a patient, but without training, are you sure you'll know what to do once it arrives?

For Marian, music therapy was not about fond reminiscence or reducing agitation. It was about working through the trauma of her childhood.

In our sessions, a pattern developed. Marian would sing variations on "Wade in the Water" as I accompanied her on the piano. The song, first published in a book of spirituals made famous by the Fisk Jubilee Singers, is associated with the Underground Railroad. The story goes that Harriet Tubman repurposed the lyrics as encrypted directions to an escape route northward for people fleeing slavery.

Soon, something remarkable happened. Marian began to exclaim her internal reality in song. She improvised extended bluesy recitatives from the opera of her life.

One day I sang to her, "How you feeling now?" She responded, in perfectly shaped musical phrases:

So bad, so bad! Mmmm.

I wish I had another mother to look after.

Love my mother

And my brother,

Plus some other people outside.

They're trying to help me out!

They don't know nothing about me

But they know me.

Help me, Lord Jesus. Mmmm.

Sometimes she would let loose with a torrent of anguished memories that she was reliving. Marian seemed to think I was one or more of the men from earlier in her life, and on occasion she would level some bluntly sexual language at me. She would try to cajole me into doing something she wanted, or else complain bitterly that I would never get married. Once, and with a fair amount of menace, she said, "I love you. I'll cut you."

A non-therapist might see this behavior as raving delusion, but psychoanalysts call it transference, which Freud described as the redirection of the client's childhood emotions onto the therapist. Although the talking cure was no longer an option for Marian, her transference manifested itself musically, through her singing.

Marian's musical transference worked its way into my imagination and exerted an influence outside of our work together. I listened to my countertransference — the therapist's emotional response to the client — and used it as a tool in our therapy in a way that was surprising even to me.

It happened spontaneously and with no conscious intent. In the middle of a session, while Marian was singing a variant of "Wade in the Water," I intuitively made a shift in my accompaniment on the piano. Instead of playing blues chords, I switched to a piece of music from my individual practice routine.

If only the superficial is considered, my selection could not have been more incongruous. I started playing the English baroque aria "When I Am Laid in Earth," Dido's lament from Henry Purcell's opera Dido and Aeneas.

I see now why this aria presented itself to me. Its mournful, descending bass line makes its way into countless blues songs. Also, the aria's lyrics are consistent with the theme of being a runner, as Marian's daughter had described her. Dido sings her lament after her lover, Aeneas, has left her. As she gets ready to kill herself, she sings, "Remember me, but ah, forget my fate." She wants us to commemorate that she lived, but not how she died.

At the most fundamental level, it's a song about memory.

Marian's response to the Purcell was astonishing. Without hesitation, she started fitting her own musical material into the container I provided, and she did so in a musically sophisticated way. Her phrases perfectly matched the structure of the aria, and over the 17th-century bass line she built her own harmonies that remained consistent with American vernacular chord extensions. We had created a mashup between English baroque opera and Negro spirituals.

Marian sang at length about longing, grief, and abandonment:

Oh, please. Oh, Luther,

Please come home to me.

'Cause my mother come back, oh, please.

I love Luther man.

Wade in the water.

Please come home.

Oh, please, in the water.

Ah, Lord.

Ah—

Then she broke down sobbing.

Although it might have seemed to her nurses like agitation, it was a direct and powerful statement of her reality. If Freud had been sitting in my chair, he would have called it catharsis.

Music was at the center of Marian's being. Holding her musical utterances, and reflecting them back to her, was perhaps the only avenue to self-actualization available to her at this point, near the end of her life.

If we want person-centered dementia care to replace the warehousing and sedation of Alzheimer's patients, music therapy is a large part of the conversation. Music's special ability to reach people with dementia does more than afford us the opportunity to understand the disease better — it presents us with a mandate. In the case of people like Marian, the information we gain through music pushes us to consider agitation not from the irritated caregiver's perspective but as the outward manifestation of the patient's inner state, one that can be addressed therapeutically.

Yes, hearing a familiar song prompts reminiscence. But to take full advantage of that knowledge, we ought to go a step further. The meaningful work is what happens next.

Dean Olsher is a music therapist in New York City.

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