By the end of the 19th Century, composers, in search of new ways to organize the harmonic content of their music, composers stumbled onto an ancient solution; the pentatonic scale. Pianist and writer Marius Nordal describes the effect that hearing the pentatonic for the first time had on the French composers Maurice Ravel and Claude Debussy.
After hearing the simple but powerful spells cast by the pentatonic scale (at theL'Esposition Universelle in Paris in 1889), Debussy and Ravel tried using them to "paint" gentle scenes of water, clouds, and fog, thus ridding themselves of the old fashioned rules and structures...
The improvised quality of these Impressionist pieces must have seemed like a pretty radical idea back them because most European ears had been accustomed to hearing music as a series of predictable events, much like what you experience today in a movie or television show. By 1900, the French Impressionist composers had gotten rid of distinct musical narratives and were using the newly "discovered" pentatonic scales to portray hazy and ill-defined without much traditional melody or even a sense of beat. They were creating trance pieces that relied on the timbres (sound color) of various instruments to canvey mood rather than melodies. Typical titles were, Nuages (Clouds) by Debussy and Jeux d'Eau (The Play of Water) by Ravel.
- From The Wisdom of the Hand: A Guide to the Jazz Pentatonic Scales by Marius Nordal, (Sher Music, 2015)