What creates music?

Music has "been" almost as long as man has learn to speak. Almost everybody in this world has a special relationship with music. Some have their favourite songs, some favourite artistes, some favourite groups, some favourite genres of music and some people listen to anything. Some people listen to music when they are alone, some people listen to music when they are working, some spend some part of their day just to listen to some music, some others dance to it.

What is it in Music that is different from a sound? We also hear sounds everyday, but we do not like to listen to the sound of an engine, or a horn or something breaking and so on. What is the inherent quality of music which makes it different from a sound, which makes music so endearing to the listner?

A very simple difference between a musical note and an arbitrary sound is the nature of music sounds to have a longer duration. But a more important property for musical notes is to have a base frequency. In lay mans words, every musical sound has a pitch. All the other sounds (non-musical) also have a base pitch but it is just the sound of a random mixture of different frequencies all together. Out of all these frequecies, the more predominant one could be called the base pitch of a non musical sound. (Ofcourse there are more ways to define the pitch of a non-musical sound)

Musical notes too have different frequencies (besides the base frequency), but it so happens that these frequencies are all multiples of the base frequency (Pitch). Infact a sound with just one frequency does have musical content, but does not sound pleasing to the ears.

Let us first try and interpret what frequency means. Frequency gives us the intuition of something repeating. But what could be repeating in a single musical note?? The answer is ofcourse, its intensity. As we all know, sound is a property of the medium, which in most cases on earth is air. Sound propogates through air through a series of compressions and expansions. These series of compressions and expansions are called waves. Thus, whenever there is a vibrating source, then the air around it undergoes fluctuations in pressure/volume (which we called waves), which gets trasmitted all around in the same frequency of the vibrating source.

These pressure waves when they reach our ears, then are reflected on our ear-drum. Our ear-drum is an excellent sensor for these pressure waves. They are extremely thin, and a small amount of variation in the pressure around it, causes it to vibrate in the same frequency as the source interpreted by the neurons and the brain. Thus we can hear!!!

In reality, no natural vibrating source vibrates with just one frequency, their vibration is actually a sum of many frequencies, and all these frequencies are captured by our ear with great fidelity.

So if the frequency components are arbitrarily related to each other, it does not give a pleasent feeling to our brain. It is only when they are related as multiples of each other, we find some pleasure in listening to it. These frequencies related to the base or fundamental frequency are called Harmonics.

Ofcourse, any non-harmonically related sounds is not totally useless. Our speech is a mixture of both harmonically related (Vowels) and non-harmonically related parts (consonants). Again our brain has the capability to recognise different sounds, like that of an engine, a plane a horn, the cooing of a bird etc.

Let us talk more in detail about musical sound next time.