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According to the Two-component theory of tone, the principle of chroma and of height are interconnected. There exists a standard representational scheme used to show the twin principles of height and chroma which is sometimes called the tonal helix.
The tonal helix depicts the cyclical nature of tones, perceivable at once as chroma and height. The direction of pitch is depicted by the continually sprialling line. The vertical positioning of dots above one another indicates octaves.
Each dot represents one of 12 points subdividing the octave. The percieved interval between each such point is referred to as the semitone. A semitone results from the subdivision into 11 intervals, each interval of which is perceived as equal. The relation between the perception of interval of a semitone and the actual distance between the two pitches (in Hz) by which that interval is circumscribed is logarithmic.