Music in Colors

The Qualitative Nature Of Chromaticism

An important attribute of a musical composition is its chromaticism, defined first in Ancient Greek Music (West, 1994). According to that musical system, there were three genuses: the “diatonic”, the “chromatic”, and the “enharmonic”. From these concepts, the separation in “chromatic”, “harmonic”, “melodic” and “diatonic” entities has evolved for the Western music paradigm. Furthermore, additional musical phenomena have been detected in Oriental music, in Byzantine music and in prosodic vocal phenomena, which cannot be exactly categorized with these predicates for tonal distributions (Politis et. al., 2002).

Whereas the term chroma is widely used, especially in comparative musicology, there is not yet a clear definition for “musical chroma”. That is the reason why music chromaticism is yet an open research problem (both practical and theoretical). There is a great deal of many considerations and approaches from many different points of view. For instance, in the expression “European chroma, Oriental or Greek chroma” the differentiation is associated with cultures, uses of sounds and feelings. Shepard (1999) has defined with chroma the note’s position within the octave and has created a nonlogarithmic pitch helix, the chroma circle that clearly depicts octave equivalence. This has led to rather complex pitch-space representations in which the chromatic tone scale, the circle of fifths, octave circularity and other properties are all accounted for. This approach perceives chroma as extension to the concept of tonality. It has been argued that the dimension of tone chroma is irrelevant in melodic perception (Idson & Massaro, 1978).