Composers of Music in Extremely Modern Style.
Claude Achille Debussy.
Courtesy of Roland Manuel.
Maurice Ravel.
Leaders of the French Impressionistic School.
Having said that tonality is a system in which all tones gravitate to a central tone (they all come home to roost!) it is not difficult to understand through the formation of the word poly—many, tonal—tones, that it means the use of several keys or tonalities at the same time, a counterpoint of key against key, or scale against scale, instead of note against note as it was in the Golden Age of Polyphony. Think of a cantus firmus in C major, and a counter melody in F♯ minor! (Between ourselves if skilfully handled, it has possibilities!) Ravel, Milhaud and Honegger know how to do it. Of course in the old system we change from key to key by means of a musical bridge called modulation, but in polytonality, the bridge is discarded, and the unrelated keys are heard piled on top of each other in layers.
Atonality, the system which Schoenberg and his followers use, is based on the chromatic scale of twelve half steps, on each one of which, chords (major and minor) may be built. This gives a more varied tonal paint-box than the old diatonic modes and the chromatic scale of former days, for it has now become an independent scale, and is not a part of the diatonic family.
Multi-and Poly-Rhythms
Rhythm also reflects this age of unrest, and there have been decided changes which seem to return to the Middle Ages to the period of bar-less music writing. Instead of finding a piece written throughout in ¾ metre or ⁴⁄₄, it will be multi-rhythmic or poly-rhythmic. Multi-rhythmic means many shiftings from one rhythm to another; poly-rhythmic means a counterpoint of different rhythms all played at the same time. The English composer, Cyril Scott, uses multi-rhythms (where almost every measure changes its metre), and the French Florent Schmitt uses poly-rhythms, (for example, triplets against eighth notes in common time in the right hand, and ⁶⁄₈ metre in the left).