Sacks begins his neurological career and witnesses music's remarkable therapeutic power on Parkinson's patients for the first time.

Tony Cicoria survives a lightning strike and develops an overwhelming obsession with playing and composing piano music.

Salimah M. has a grand mal seizure and afterward feels an intense, transformative need to surround herself with music.

Mr. S. experiences a temporal lobe seizure preceded by hearing a hauntingly familiar but completely unidentifiable violin melody.

Sacks explains that imagining music activates the same brain areas as actually listening to it.

Sheryl, a patient with progressive hearing loss, begins experiencing loud and intrusive musical hallucinations that disrupt her daily life.

D. L., born with complete congenital amusia, tells Sacks she has heard all music as meaningless noise her entire life.

Musician Jacob L. realizes he can no longer accurately perceive tones in higher octaves due to cochlear hair cell damage.

Musician Clive Wearing contracts encephalitis and is left with amnesia so severe his memory resets every few seconds.

Sacks visits Clive Wearing and watches him play and improvise on the piano with full emotion and technical skill.

Sacks injures his leg in a climbing accident and discovers that a Mendelssohn concerto's rhythm restores his natural walking.

Music therapist Kitty helps Sacks's encephalitis patients at a hospital achieve speech and movement through rhythmic music.

Harry S. suffers frontal lobe damage from an aneurysm and loses all emotional response except when he sings.

Vera develops an unexpected and intense love of singing and improvisation after being diagnosed with frontotemporal dementia.

Sacks visits a camp for people with Williams syndrome and meets Gloria Lenhoff, who sings opera in 30 languages.

Pool 1 traces the most significant cases and arguments in Sacks's book, beginning with his earliest clinical observations and moving through the most famous patients he encountered. It opens with Tony Cicoria's dramatic transformation after a lightning strike and advances through Sheryl's musical hallucinations and Jacob's cochlear amusia. The centerpiece is Clive Wearing, whose catastrophic amnesia left his musical abilities entirely intact. The pool also covers Sacks's own leg injury healed through rhythm, the dramatic effects of music on Parkinson's patients, and Harry S., who could feel emotion only while singing. It concludes with the hypermusicality of Williams syndrome and Sacks's reflections on music as an innate human characteristic.

The headline cases that define the neurology of music.

Sacks introduces the term musicophilia to describe the innate and universal human passion for music.

Neurologist Macdonald Critchley documents patients in the 1930s whose seizures are reliably triggered by specific types of music.

A patient with severe musicogenic epilepsy undergoes surgery to remove part of her temporal lobe and is freed from music-triggered seizures.

A Parkinson's patient becomes frozen in a catatonic state, entirely trapped by a relentless earworm playing for hours.

Dwight Mamlok begins hearing imaginary music layered onto airplane engine sounds, which eventually spreads into his daily life.

Composer John C. develops an internal musical iPod that automatically transcribes popular songs into piano arrangements he never chose.

Dr. Jorgensen loses hearing in his right ear after an operation and finds that music loses all emotional impact.

Martin, left with severe intellectual deficits after childhood meningitis, develops an extraordinary ability to reproduce complex melodies after one hearing.

Solomon's dyskinesia produces involuntary lurching sounds until he discovers that the Jewish practice of davening gives those movements form and purpose.

Sydney A., who has Tourette's syndrome, develops complex expressive musical tics involving full-body gestures and sounds triggered by music.

Physician Silas Weir Mitchell observes that Civil War veterans who lost limbs continue to feel vivid sensation in the missing limb.

Pianist Paul Wittgenstein loses his right arm but continues performing by precisely imagining the movements of his missing hand.

Pianists Gary Graffman and Leon Fleisher publicly describe their gradual and debilitating loss of finger motor control to dystonia.

Sacks dreams of Mahler's Kindertotenlieder the night after resigning from a children's hospital and is startled by the precision of his subconscious.

A music therapist writing to Sacks describes music as a can-opener for people's memories while treating Alzheimer's patients.

Pool 2 covers the supporting cases and secondary figures that enrich Sacks's argument without appearing in Pool 1. It opens with the coining of the term musicophilia and moves through early historical observations of music-triggered seizures, relentless earworms, and the spread of musical hallucinations into daily life. The pool includes figures such as Martin, whose childhood meningitis gave rise to extraordinary savant abilities, and Dr. Jorgensen, who lost stereo hearing and with it music's emotional power. It also covers the physical communication breakthroughs of Solomon and Sydney A., and the Civil War origins of phantom limb research. The pool concludes with the public revelations about musician's dystonia, Sacks's prophetic Mahler dream, and a music therapist's unforgettable description of music as a key to memory.

Supporting cases and secondary stories spanning the full book.

Psychologist William James theorizes that music evolved alongside other fundamental human adaptations such as technology and the capacity for pleasure.

Tony Cicoria's doctor declares him fully recovered after the lightning strike, unaware of the musical obsession already forming inside him.

Musician Eric Markowitz develops a brain tumor that causes conscious seizures in which internally generated music feels dangerously and hypnotically consuming.

Neuroscientist Rodolfo Llinas identifies the basal ganglia as the source of spontaneous musical imagery because of its constant unprompted activity.

Sacks experiences temporary amusia and suddenly hears his beloved Chopin as nothing but irritating and meaningless banging.

Composer Rachael, after years of silence following her head and spine injury, begins working on her first new composition.

Jacob L. receives a commission to score a large orchestral work and uses it as the drive to restore his perception of higher tones.

Dr. Jorgensen trains himself to perceive stereo sound through visual cues and memory despite having permanently lost hearing in one ear.

Clive Wearing's wife Deborah fights to have him transferred from a psychiatric institution to a smaller and more personal care facility.

An aphasia patient who could not speak learns to produce short phrases after months of music therapy involving simple singing.

A physician temporarily loses all emotional response to music following a concussion, revealing a physiological basis for musical feeling.

Sacks's grief following his mother's death is finally released when an unexpected piece of music breaks through his emotional numbness.

Larry arrives at neurologist Dr. Miller's office singing loudly and talking endlessly, displaying the hypermusicality of frontotemporal dementia.

Neuroimaging research by Levitin and Bellugi reveals that people with Williams syndrome show unusually broad brain activation in response to music.

Alzheimer's patient Woody demonstrates a relatively intact sense of self and deep emotional connection to his favorite songs when Sacks meets him.

Pool 3 highlights the moments of revelation, adaptation, and emotional breakthrough that shape Sacks's core claims. It begins with William James's foundational evolutionary theory and moves through a series of turning points: Tony Cicoria's doctor missing the emerging transformation, Eric Markowitz's dangerously consuming musical seizures, and Sacks's own sudden and bewildering amusia. The pool tracks figures who push back against neurological loss, including composer Rachael returning to her craft, Jacob willing his brain to rehear lost tones, and Clive Wearing's wife securing him a better life. It concludes with Sacks's grief broken open by music, a dementia patient's explosive hypermusicality, and Alzheimer's patient Woody's touching demonstration that music preserves the emotional self.

The discoveries, adaptations, and emotional breakthroughs that drive Sacks's argument.