# Glissando

I find it odd that the musical chromatic scale is made up of twelve notes, the thirteenth repeating the starting note an octave higher. And that the major and minor scales are made up of seven notes each. I’m not suggesting that any other numbers would be any more logical; merely that having any number higher than two play such a pivotal role in something as fundamental as music seems bizarre.

I wonder whether relative pitch resonates (in the mind sense of the word) with us as humans more than it does with other animals. And would we find it musically odd our scale were broken into any number other than twelve intervals? After all, pitch is a continuous scale (ask anyone who listened to me play the violin), so have we artificially manufactured the notes that we know and love? (I’m guessing that there is something inherently significant about two notes an octave apart, given the way they resonate with one another.)

4 Responses to “Glissando”

1. Tom on July 14th, 2008 00:14

Yes, it’s x2.

2. Steve on July 14th, 2008 09:12

The splitting of the octave-to-octave split into 12 equal divisions is by no means universal, and some music in non-western cultures has 22 or 30+ divisions, which often sounds a bit weird to those expecting a 12 note chromatic scale.

Splitting semi-tones is sometimes used in western music, though this is often just for atonal effect (such the string bend in the intro to Purple Haze for a cheesy example).

I remember reading once that the magic number of 12 is down to simple maths (in that 12 is divisible by 1, 2, 3, 4, 6 and itself) and this creates diversity of composition and structure without sacrificing recognsable harmony. Don’t know how true this is, but it sounds reasonable enough.

I’ve often wondered about octaves though, and what makes them identical, but different. I’m sure there’s a clever explanation for it all; I just don’t know what it is…

3. Tom on July 14th, 2008 10:14

An octave is a doubling of the frequency of the note.

Thus if you think of a note as a standing wave of appropriate wave length then superimpose a wave with half that wave length then you can see how they fit together nicely which we describe as resonating when heard.

4. Steve on July 14th, 2008 12:59

See? I knew there was a clever explanation…