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Diatonicism (from Greek dia tonikos, ‘at intervals of a tone’) is an (artificial) acoustical system which underlies most Western music. The distance between a sound and the same sound an octave lower or an octave higher is divided into groups of tones and semitones: these groups are modes or scales. (A mode divides the octave into six or seven units, counting the starting-note, and a scale into eight.) The diatonic scales are major (tone-tone-semitone-tone-tone-tone-semitone) and minor (tone-semitone-tone-tone-tone-tone-semitone—often nowadays with the last two tones replaced by semitone-minor third).
In diatonic music, every sequence of notes in a melody—jump from note to note—or chord in the harmony must conform to the basic scale, and the music is said to be ‘in’ the mode or key named after the note on which that scale begins and ends. Originally, notes outside the system were not allowed, but as music became more elaborate, the idea of modulation was introduced: using notes outside the basic system to shift the music briefly or for longer periods into other systems (see chromaticism).
The ancient Greeks, who used modes—which are like scales, except that each of the seven modes has a slightly different arrangement of tones and semitones from all the others, and therefore a slightly different ‘character’—assigned specific subjective ‘meanings’ to each mode. The doric mode was warlike, the lydian mode amorous, the phrygian mode pastoral, and so on. Music with certain associations had, by convention, to use the appropriate mode. Scales, because apart from their starting-point, they are identical to one another, have no such associations. However, in Europe in the 17th and 18th centuries, when the comparatively simple nature of brass instruments meant that they could only play ‘in’ certain scales, those scales were associated with music using brass instruments, and the occasions for which it was written. Hunting and military music, for example, was usually in B flat, C or D. By the same token, pastoral music, using flutes, was often in G (their natural scale). These associations persisted, to some extent, even after instruments were developed which could play all the chromatic notes with equal ease. At the end of the 19th century, the composer Scriabin and others experimented with assigning (or pretending to discover) specific psychological associations with this key or that, and composing music accordingly, but the idea had only a brief vogue.
Diatonic music has been standard in the West at least since ancient Greek times, and perhaps longer (none survives, so no one knows). It has constantly been nudged by other systems—folk music, for example, often divides the octaves into units smaller than tones and semitones—and it has been enriched and modified by a continual expansion of the use of chromaticism. But it has never been displaced, and is the root of most of the Western musical experience, in all forms. At various times, attempts have been made to show that it is endemic to sound itself, that it is acoustically validated. But modern scholars say that this is wishful thinking, and that we assume it simply because our ears have been conditioned to it over thousands of years. In our pluralist modern age, diatonicism is beginning to be subverted both by our increasingly familiarity with non-diatonic music from other traditions (especially from Africa and East Asia), and by the use of electronics (which allow infinitely varied divisions of the octave). The process, however, is still not far advanced, and may, like chromaticism, end up as an enrichment of diatonicism rather than its replacement. KMcL
See also intonation, tuning and temperament; tonality. |
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