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Why do we only use 12 notes in Western music?
Richard Ellam
Bristol, UK
Notes with frequencies that are in simple whole-number ratios, like 1:2, 2:3 or 4:5, sound good when played together. This is the basis of musical harmony. After unison (1:1) and the octave (2:1), the next most harmonious interval is 3:2, known as a perfect fifth.
Starting at any (low) frequency, you can construct a series of tones, each a perfect fifth (3/2 the frequency) higher than the one below. The twelfth tone in this series sounds like a (much) higher…
