Mode Mixture in Debussy’s “Beau Soir”

Today, I have decided to analyze Debussy’s usage of mode mixture in the song “Beau soir,” which translates to “Beautiful Evening.” It is one of Debussy’s earlier songs, composed around 1883. Indeed, Debussy relies on mode mixture in this piece to help convey his colorful description of the text.

Roman Numeral Analysis: The tonic key of the piece is E Major, but m. 20-27 is in the key of F-sharp minor (ii).

m. 20-23: ii: i, IV7, i, IV7

Past this point, the analysis gets complicated for me to analyze with absolute certainty, but I’ll give it my best shot.

m. 24-27:ii: iihalfdiminished7, VII43, iihalfdiminished7, VII7 (could be form of mode mixture, these are odd chords to alternate between)

Text: m. 20-27:

Un conseil de goûter le charme d’être au monde

Cependant qu’on ext jeune et que le soir est beau

Translation:

A counsel to relish the charm of being in this world

While one is young and while the evening is beautiful

The song “Beau soir” is about the beautiful setting of the sun. However, there is a hint of sadness in the song as well, as the beauty of the evening sun will eventually fade. Then, we will be left in the darkness of the night. The beginning of m. 20 in the key of F-sharp minor and alternating between i and IV7 (m. 20-23), a mode mixture harmony borrowed from the parallel key of F-sharp Major (mostly, with the exception of the A natural, which is scale degree 3 in F-sharp minor) creates a bittersweet feeling: The minor i creates the sadness of knowing the evening sun will eventually fade, while the IV7 embraces the warmth and beauty of the sun. Then, passion and desire for the sun’s beauty increases starting m. 24. Debussy marks animato poco a poco e crescendo: The iihalfdiminished7 (m. 24, 26, ii usually fulldiminishedii(7) in minor key), and VII43(m. 25) function to increase build up to the climax chord, VII7 (m. 27). The strongest climax of the piece naturally falls on “beau,” or “beauty,” on m. 26-27 to emphasize that word, which is the most powerful and colorful word used to describe the sun. The animato poco a poco e crescendo (m. 24) adds to the feeling of the brevity of the sun’s beauty before it must go and set past the sea. The duplet against triplet patterns in the piano throughout m. 20-27 also give the listener a sense that the piece is going into more motion, alluding to the inevitable climax (m. 27).

Debussy clearly shows the performers what he wants through his markings such as with the aforementioned animato poco a poco e crescendo. m. 27 is the only time forte is written in the entire song for both the voice and piano. The rest of the piece is either pianissimo or piano. Therefore, the climax must be special, and the performers must passionately embrace the bittersweetness and brief climax (m. 27) of m. 20-27, which can be done so by following Debussy’s markings, especially the animato poco a poco e crescendo (m. 24), and also by stressing the first beat of m. 27, particularly the melodic octave D naturals in the piano. I don’t think that tempo rubato is necessary; the climax is special enough the way Debussy wrote. The mode mixture of m. 20-23 proves essential in starting the bittersweet mood and longing for the sun and driving this section into motion. m. 20-27 is pleasant for listeners for the same reasons that it is for the performers. Due to the climax’s brevity and build up through use of mode mixture, m. 20-27 creates absolute magic for the audience and performers alike.