La Cathédrale Engloutie by Claude Debussy

In the impressionism era, any exoteric about impression such as paintings or music would like to show people that picture in color with a completely abstract and beyond reality. The French composer,Claude Debussy (1862-1918) is a leader of the impressionism in field of music.Debussy likes to place the title of a work at the end of the peice,that allows pianists to feel and imagine the music intuitively before they find out what Debbusy intended to compost about. La Cathédrale engloutie (The Sunken Cathedral,1910), is the tenth prelude from Debussy's first of the two volumes book, Préludes.This solo piano peice illustrates the characteristics of the form, harmony, and content developed by Debussy.The piece is based on an ancient Breton myth in which a cathedral, submerged underwater off the coast of the Island of Ys, rises up from the sea on clear mornings when the water is transparent. Sounds can be heard of priests chanting, bells chiming, and the organ playing, from across the sea. Accordingly, Debussy uses certain harmonies to allude to the plot of the legend, in the style of musical impressionism.
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As Debussy's common compositional form,this peice is in binary form. However, the peice might also follow as introduction-Section I-Section II- Section III- Section IV- Codetta. From m.1 to m.15 is an introduction like begining. It can be divided further into three subsections: Subsection i(m.1- m.6),subsection ii (m.7-m.13) and subsection iii (m.14, m.15). To begin the peice, Debussy uses rising parallel chords on the open fifth and octave that are focused on pantatonic scale. Subsection ii in modulation which anticipates the ideas in Section III. Subsection iii restates the rising pantatonic idea . Section I strats from m. 16 through m. 27. Again, it plays with pentatonic groupings and similar progressions of rising chords. Through a transition into Section II (m.28-m.41) features a progression of parallel triadic chords. Meatures 42 - 46