I Heard There Was a Secret Chord: Music as Medicine

by Daniel J. Levitin

As far as we know, all societies in some way acknowledge the special status of the octave, which is produced by a ratio of 2:1 (in string length, the length of a pipe, and indeed, the ratio of vibrations). Pentatonic (five-note) scales are common, and our American blues scale is a pentatonic scale with an added “blue” note, the tritone. In our Western musical system, the octave is divided into 12 equal steps, and we tend to use only seven of them at a time; depending on which seven, and the order we play them in, we get a major or a minor scale. Music in Arab and Indian cultures uses microtones, notes between the notes on our piano keyboard; this is one of the reasons their music sounds exotic to Westerners. Some writers have claimed these constitute 48-note scales, but the reality is that most of the microtones are used as passing tones and ornaments, not components of a melody.