I. Pitch space analogies:
a. Vertical


Pitch characterized from low to high in a vertical dimension.

Physical analogy: vertically oriented wind instrument technique (clarinet, sax), guitar technique: low string (top) to high string (bottom) in one fingering position. Or, with cello and double bass technique, top/low and bottom/high on each string.

By theoretical convention, music notation represents ‘higher’ notes in a vertically higher position on the staff.
While lower pitches are represented as lesser values in hertz/cycles per second, the frequency relationships applied to visual colors are not conceptually organized in this type vertical, low-high, fashion.

b. Horizontal


Pitch characterized from low to high in a horizontal dimension, left/low to right/high.
Physical analogy: keyboard instrument technique, guitar technique: one string low to high.

c. Physical Proximity


lower pitch = distal higher pitch = proximal.
Physical analogy: stringed instrument technique, trombone.

d. Physical Tension


Lower pitch = relaxation; higher pitch = tension.
Physical analogy: vocal and brass instrument technique.

II. Absolute Pitch Recognition:
Awareness and memorization of unique spectral ‘signatures’ (peaks/dips of harmonics) inherent in each individual tone or harmonic configuration. Acontextual perception, separate and simultaneous intervallic relationships not analyzed and utilized. Analogy: ‘green‘ absolutely defined in isolation as a static entity; brightness, hue and saturation
interrelationships ignored.

Perception of a fixed static pitch array unrelated to harmonic (polyphonic) context.
Dynamic and unique intervallic and harmonic interrelationships unrecognized.

III. Relative Pitch Recognition:
Awareness of contextual pitch inter-relationships. Contextual perception, separate and
simultaneous intervallic relationships utilized analytically.

At a more refined level, awareness and adaptation to contextual pitch deviations in harmonic context. Analogy: ‘greenish’, relative to visual context; surrounding brightness
hue, and saturation interrelationships recognized.

IV. Global pitch A = 440 Hz
This official standardization has been a recent phenomenon over the last 80+ years, initially adopted in 1939, by the British Standards Institution (BSI). Prior to this, localities had varying pitch standards. In 1955, the International Organization for Standardization (ISO) endorsed A440 as a tuning standard.

This standardization appears to have been a compromise between the lower pitch levels of the 18th century composers whose works made up a large basis of the concert repertoire and the higher, more brilliant sounding pitch levels utilized my the 19th century wind instrument manufacturers.

The basis of the decision to fixate the pitch A4 on A440 was based on committee acceptance, not any analysis of frequencies inherent in nature. The result is a dissociation of the fixed musical pitch palette from commonly occurring vibration frequencies in the natural world.

Organs (tuned at the time of building/creation) show a historic variance between
roughly 373 Hz-465 Hz before standardization.

A need for uniformity was appreciated due to the strain on vocalists singing scores in (mostly) higher orchestral tunings in different locales.

Orchestral performances gained the tendency toward increasing sharpness which was perceived as more  exciting and brilliant.

Analogy: The current vogue of hourglass shaped mixes in recorded music. These recordings are generally perceived as louder and more brilliant or conversely as brittle and cold. This result is achieved by characteristically boosting the high (2-4 kHz) and low frequencies creating an effect of broadly decreased middle frequencies. The ‘expendable’ middle frequencies are generally perceived as warm and fat/thick or conversely as muddy and indistinct. (i.e. phonograph recordings of Crosby, Stills & Nash).

V. Micropitch Perceptual Categorization

Analogy: for many untrained observers, the colors Aqua, Azure, Cobalt, Teal, Navy, Turquoise, etc. are visually perceived without fine discrimination and conceptually reduced to the learned category of Blue.
Since these subtleties of color are well within our perceptual discrimination, this type of analogical conceptual categorization could be an effective bridge in creating nuanced pitch categorical classifications and vice versa, using sound to facilitate increasing levels of visual color awareness and conceptual refinement.