Do you see colors when you hear music?

Synesthesia is a rare neurological occurrence that associates colors with other senses. For example, when a person with synesthesia hears or sees the number "6" they may associate that number with the color blue, for no apparent reason. When a person associates musical pitches with specific colors; this is known as chromesthesia or sound-to-color synesthesia.(1)

Those with this disorder can experience the sound-to-color phenomenon in two main ways. One is actually seeing colors in the physical world (this is known as "projecting"). Others perceive the colors in their mind (know as "associators"). For some, the synesthesia is triggered by speech, but for the majority of people, hearing musical pitches is the main trigger. Only 33% of people who have synesthesia claim that they can willfully ignore it.

Scientists are still unclear as to why this phenomenon occurs. A popular theory suggests that when certain parts of the brain are engaged, they "cross-activate" other parts, resulting in the perception of senses in an unconventional way. Studies have shown those who are artists/musicians are twice as likely to be a synesthete (one who has synesthesia) than the general population! (2) In addition, those with good absolute pitch (the ability to define pitches from one reference pitch) were found to be more inclined to have synesthesia. This fact is surprising considering those with perfect pitch (the ability to define any pitch without the use of an external reference pitch) would seem to be more likely to associate known pitches with known colors.

Here are some famous musicians who have or have had synesthesia: