harmonizations II: scales & modes
Unlike the 18th and 19th centuries where the minor and major scales formed the basis of a tonal spectrum in Western classical music, developments in the 20th century show an explosion of the use of diverse scales. Some of these scales already had a long tradition, both in Western classical music and music from different cultures and parts of the world; other scales were new. Both scale and harmony influenced each other in the sounding musical result, giving infinite possibilities for creating new tone combinations.
A short overview of 20th-century scales:
revival of traditional modes like the medieval church modes, etc.
modern modes and scales like the octatonic scale, Messiaen's modes of limited transposition, etc.
scales from different cultures such as the Arabic maqam, pentatonic scales, whole tone scale, blues scales, flamenco scales, Indian melakarta scales, etc.
tempered scales derived by dividing the octave into multiple equal steps, etc.
The following example shows some of the medieval church modes:
Chapter XVI of Olivier Messiaen's (1908-1992) Technique de mon language musical (1944) contains several 'modes of limited transpositions'. The following example shows the 4th mode followed by a sucession of chords:
The following example shows one of the 72 Arabic maqams:
Nicolas Slonimsky's (1894-1995) Thesaurus Of Scales And Melodic Patterns (1947) shows many examples of divisions of the octave in equal parts, diminution and arpeggio techniques, and melodic patterns. The following example shows how an octave is divided into four equal parts, how notes are then added and the chord progressions that result.