Why does every instrument produce an indvidual sound?

Answer 1

Each Instrument has its characteristic sound primarily, but not entirely, because of its sound "spectrum," the combinations of the pitches in its tone. When we listen to the sound of an instrument playing a sustained note, we hear one "pitch." But that note is acoustically "complex"; that is, it is a blend composed of a number of frequencies (pitches), each with its own intensity. When the combination of frequencies and their intensities varies, the quality of the instrument's tone changes, and we recognize a different instrument as the source of the note. Just as an artist can create varying shades of green by mixing varying yellows and blues, a pipe-organ (or an electronic device) can "create" -- imitate -- the sounds of other instruments by combining the various frequencies, each with its required intensity, to match the sound-spectrum of the instrument that is being imitated. Other elements determine to the characteristic tone of the various instruments, but sound-spectrum is the main one. For an advanced discussion of the issue, and of a great number of other issues in the science of the acoustics of music, go to http://www.phys.unsw.edu.au/jw/SiteMap.html#general At the page, click on "General Topics" and then on "What is a sound spectrum."