PITCH means the highness or lowness of the sound. Some pieces need high sounds and some need low, deep sounds. Some have sounds that are in the middle. Most pieces use a mixture of pitches.
the visible light spectrum
What is the visible light spectrum? The visible light spectrum is the segment of the electromagnetic spectrum that the human eye can view. More simply, this range of wavelengths is called visible light. Typically, the human eye can detect wavelengths from 380 to 700 nanometers.
