Wednesday, January 18, 2012

What Sounds Weird Now?

In music we currently subdivide the octave into 12 equal tones, a system known as Equal Temperament (or Equal Temperament 12 to be more precise). This system sounds natural to us because it resembles the perfect ratios we want to hear from music. For examples, a ratio of 3:2 represents a perfect fifth (a C note to a G note). A ratio of 4:3 represents a perfect fourth (a C note to an F note). These perfect ratios sound consonant to the ears. Equal Temperament 12 does not match these ratios exactly. If it did, we would not be able to easily play music in every key. A tradeoff is required, and Equal Temperament 12 is generally considered to be the best system for being able to play in all keys, while still coming close to the perfect ratios we enjoy.

It is possible to divide the octave in other ways too. Consider Equal Temperament 15. It is the same principle, the only thing that changes is the number.
Listen to this composition by Jonathan Rabson that I found on Youtube:

Of course, it sounds pretty weird. But think about what it would be like if we only heard Equal Temperament 15 our whole lives, and then someone played in Equal Temperament 12? How would that be? I actually don't know the answer to this question. On one hand, Equal Temperament 15 is further away from the perfect ratios that humans seem to enjoy. However, if we had no context for Equal Temperament 12, I'm not convinced we would necessary be naturally drawn to it.


  1. Well, the Human Mind is set up to prefer consonance (Trainer 1998 where he studied the responses of infants to either consonant and dissonant intervals), so the 12 tone scale probably would sound odd or different, but likely not unpleasing.

    However, the Equal Temperament 15 would in my opinion sound pleasing if you had grown up with it. Take the Indonesian musical tradition of the Gamelan. It creates a micro-tonal tuning element by use of two separate but simultaneously utilized musical scales. It would often sound unpleasing to us familiar only with Western Classical, but to the Indonesians it is very pleasing.

    One thing to consider is George Miller's 7+/-2 number for information processing. I think for a scale to sound pleasing it would need to conform to the abilities of our human mind. Meaning that a melody based around a chromatic scale in Equal temperamental 15 might be too much for our brains to handle (depending on the way the melody is set up) to sound pleasing.

  2. That's certainly true about a relatable melody. I think a lot of people have trouble relating to 12-tone music for that reason. Even though it is in a familiar temperament the melodies are sometimes obscure.
    I think in any temperament you can have qualities that are inherently musical that will draw people in.