Musical notation omits harmonics that sonograms reveal

Evidence

A sonogram is a cousin of musical notation; see figure 5.1. In musical notation, the time is only loosely proportional to the horizontal distance on the page, and the notes give only the lowest, or fundamental, frequency to be played, whereas in sonograms the higher harmonics of a given note will also appear. (Harmonics are integer multiples of a given frequency— for example, 200 Hz, 300 Hz, and so on are harmonics of 100 Hz.) The frequency (vertical) axis in musical notation is logarithmic, since each octave is a factor of 2 higher in frequency, so octaves are equally spaced on the musical staff. Thus A220 and A440 are an octave apart, separated by 220 Hz and a certain distance apart on the scale, but A440 and A880 are also an octave apart and the same distance apart on the scale, but separated by twice as much in frequency, 440 Hz. Sometimes it is best to plot log(frequency) rather than frequency in sonograms too. — Eric J. Heller, Why You Hear What You Hear- An…, 440

Categorization

• XREF: The logarithmic-octave spacing echoes how the ear perceives pitch ratios, connecting signal analysis to auditory perception. — connects to: Sonograms visually expose vowel formants as enhanced frequency bands
• DEFINE: Explains harmonics and why musical notation omits them while sonograms include them.
• corroborated: 2 independent passages support this claim — Eric J. Heller, Why You Hear What You Hear- An…, 440