Music is one of the most expressive art forms ever perceived by man. Music enriches the environment with lively and sometimes even melancholous strains. However all music, classical or folk, for that matter gets the form from the musical notes. Classical Western Music is even more dependent on chords, the sounding of two or more notes musical notes simultaneously.In this article, rather than describing about how music and physics evolved hand in hand, the author shall venture out to explain the physics of chords as it was understood long ago and how is it understood now.
The Physics Of A Chord:
First, before we get into too much technicalities, lets begin with what is a chord?
'A chord is the simultaneous and deliberate sounding of two or more musical notes which is pleasing to the ear'. Now, we have included the factor of being pleasing to the ear for defining a chord. So we should see what makes a chord sound pleasing to the ear.
Now, there are basically seven notes in the musical scale. According to Carnatic music, they are Sa Ri Ga Ma Pa Dha Ni. Now, they are arranged in increasing order of frequencies. If Sa corresponds to 1 unit of frequency then the other notes are as follows:
Sa- 1, Ri- 9/8, Ga-81/64, Ma-4/3, Pa- 3/2, Dha- 27/16, Ni- 243/128.
Now, it is a common observation that every fifth note when sounded together sounds pleasing to the ear. Now, that implies Sa and Pa should sound consonant (Pleasing to the ear). Now,
The frequency of Every fifth note / The frequency of the base note = 3/2
So, it means any two frequencies such that one frequency is 3/2 times the other should sound pleasing when sounded together. This was first suggested by the Greek philosopher, Pythagoras. The reason for why this works is still not quite clearly understood, but it definitely works. The reader, if he has a piano or a keyboard, shall have an interesting time playing notes which are a fifth to some other note. They shall sound particularly and distinctly pleasant.
In the forthcoming articles, the author shall try to explain why a few notes sound solemn and a few others sound cheerful, and also briefs the reader how this may be used to the advantage of a composer.