The role of synaesthesia in reading written musical key signatures

This study is the first empirical demonstration of synaesthesia for reading written musical keys signatures. Nine music-color synaesthetes and 9 controls took part in 5 experiments that aimed to confirm the authenticity of synaesthesia for reading musical keys, and to demonstrate that this type of synaesthesia is linked to conceptual rather than to purely perceptual processing of the inducing stimulus. First, the existence of a synaesthetic association with written musical keys was validated in an objective manner by employing 2 measures of consistency as diagnostic criteria. Second, the automaticity of the synaesthetes’ responses was tested by demonstrating the presence of interference when naming synaesthetic colors for incongruent pairings of color and musical key. To test whether a change in form altered the concept of the musical key, stimuli were randomly presented in 3 separate modes (words, treble clef, or bass clef). Last, the interference of synaesthetic colors with veridical colors was assessed in a task-irrelevant manner, that is, without the need for the explicit naming of synaesthetic color. Findings showed synaesthesia for written musical keys to be a genuine form of synaesthesia elicited from the concept, or the idea, of the key.