New York Philharmonic

“Synesthesia” is a neurological condition that causes an involuntary sensory experience to be provoked from an initial stimulation of a different sensory or cognitive pathway – for instance, automatically associating colors with numbers, letters, or sounds. Olivier Messiaen, a 20th-century French composer, organist, and ornithologist, “heard” colors in all music, whether tonal, modal, or serial.