Is there a specific reason why the music notes are of the well-known frequencies? Or, the frequencies just became the de facto standard from some historical musical instrument? http://www.techlib.com/reference/musical_note_frequencies.htm I was wondering if sound processing is similar to our brain tuned to the specific light frequencies (colors). What's the science behind 7 notes? (I've heard chinese music has only 5 notes) Western and Indian classical music has 7 notes, even though both are not directly related or borrowed. Is it just a random coincidence, or there is science behind it?