Music education often emphasizes musical literacy or the ability to read musical notation. Yet a lot of people – even professional musicians struggle with it. Could musical dyslexia be the cause?
Dyslexia is a learning disability that occurs when the brain fails to process written words, even when the person was properly trained in reading. Researchers debate the underlying The causes and treatments are still unclelar, but the popular theory is that people with dyslexia have a problem with phonological processing – the ability to see a symbol and relate it to speech sounds. It is thought that dyslexia occurs in up to 10% of the population.
That’s why in 2000, Neil Gordon, a retired pediatric neurologist, proposed the idea of dysmusia, or musical dyslexia, based on growing evidence that the areas of the brain involved in reading music and text differed.
Music, like language, has a highly evolved coding system. This allows it to be written down and transmitted from composer to performer. But unlike language, music uses a spatial arrangement for pitch. The page is divided into staffs of five lines each. The higher a symbol is placed on the staff, the higher the pitch.
Unlike letters in text, pitches can be stacked, indicating simultaneous performance (chords). Music also uses a system of symbols to indicate how pitches should be played. Symbols can indicate duration (rhythm), volume (dynamics) and other performance cues. Music also uses written words to indicate both the expressive features of the music and the lyrics in vocal music. Lyrics can be in languages that the performer doesn’t speak.
Considering the differences in the physical features of the written systems, it makes sense that the brain would read music and text differently.
Music reading is truly a whole brain activity – it includes motor, visual, auditory, audiovisual, somatosensory, parietal and frontal areas in both hemispheres and the cerebellum. With training, the neural network strengthens. Even reading a single pitch activates this widespread network in musicians. Text and music reading are largely independent, even though they share some networks. The pattern of activation for reading musical symbols and letters is different across the brain.
Research starts to imply how a specifically musical dyslexia could occur. The disability may be centered on pitch or musical symbols or both. There isn’t a conclusive case of musical dyslexia reported yet and efforts to determine its effects have been inconclusive.
A neurologist and amateur pianist named Ian McDonald documented the loss and recovery of his own ability to read music after a stroke, though his ability to read text was unaffected. Oliver Sacks described the case of a professional pianist who, due to a degenerative brain disease first lost her ability to read music while her text reading was intact. There are also cases showing the opposite pattern, a musician lost his ability to read text, but kept his ability to read music.
There are other cases where music and language seem to be differently affected by brain damage – people who can’t speak but keep the ability to sing. The earliest report of such a case was in a 1745 article, called “On a Mute who Can Sing”.
More recently Vissarion Shebalin, a Russian composer, lost his language abilities after a severe stroke, but kept his ability to compose. Cases like this have led to the creation of a therapeutic treatment called Melodic Intonation Therapy. The treatment essentially replaces speech with song. This allows the patient to communicate verbally.
Differences in reading ability can occur even within musical notation. fMRI studies have confirmed that the brain processes pitch (spatial information) and rhythm (symbol recognition) differently. Cases have been reported where musicians have lost their ability to read pitch, but retained their ability to read rhythm, and vice versa.
Children are taught to read text, but not always taught to read music. Even when they are, inabilitiy to do so is not generally treated as a serious concern. Many gifted musicians are able to function professionally purely by learning music by ear. Among musicians, there is a wide range of music reading proficiencies. Identifying musical dyslexia could help explain why some musicians can read well and others can’t.