Chromatic Spectrum
Overview
This view shows the audio spectrum as a constellation of pitch and partial LEDs arranged in a 12-step semitone circle. This chromatic spectrum provides a unique, music-oriented view of tonal content and behaviour.
Pitch LEDs
Each pitch LED represents the state of pitch class in the audio spectrum as follows:
- Brightness represents the relative strength of the pitch class.
- A label identifies the pitch class.
- Colour represents the pitch class.
Partial LEDs
Each partial LED represents the state of a partial in the audio spectrum as follows:
- Brightness represents the relative strength of the partial.
- Radial position represents the pitch class and octave of the partial's frequency.
- The meaning of colour depends on analysis mode:
- In Spectral mode, colour represents the pitch class of the partial's frequency.
- In Perceptual mode, colour represents the pitch class of the most likely fundamental frequency of the partial.
Pitch Range and Frequencies
The pitch range of the view is A1 through G#8 on the piano keyboard.
To reveal the expected frequency (i.e. tuning reference) for a particular pitch and octave, tap on the corresponding position in the view.
To reveal the expected frequency (i.e. tuning reference) for a particular pitch and octave, tap on the corresponding position in the view.
Example: A440 Tone
Example: Complex Tone in Spectral Mode
This complex tone has 10 harmonics with a fundamental frequency of 220Hz. To the ear, the tone sounds like an A3 with a reedy timbre.
The chromatic spectrum consists of 10 partials that fall into 5 separate pitch classes. The fundamental partial is in the A3 position. Although the A pitch class is the strongest in this case, there is potential for ambiguity. To reproduce this example, set the Audio Source to Complex Tone, and set the Analysis Mode to Spectral. |
Example: Complex Tone in Perceptual Mode
This complex tone has 10 harmonics with a fundamental frequency of 220Hz. To the ear, the tone sounds like an A3 with a reedy timbre.
The chromatic spectrum consists of 10 partials that are associated only with the A pitch class. The fundamental partial is in the A3 position. To reproduce this example, set the Audio Source to Complex Tone, and set the Analysis Mode to Perceptual. |