Ravel attaches great importance to the role of melody. He once said to his student, the famous British composer Vaughan Williams, "In all living music, there is an implicit melody outline". The melody of the water demon is extremely moving. It sings freely in the irregular changes of 2/4, 3/4, 4/4 and 5/4 beats, depicting the magical and romantic impressionist artistic conception.
The music begins with an introduction of two bars, and the right hand slowly plays a dense 32-tone augmented chord. It keeps repeating alternately between major triad and his semitone, with gentle intensity, and depicts the charming scene of water waves rippling.
On this phonological background, the left hand plays a lyrical melodious theme melody, which has a long and wonderful feeling: here, Ravel handles the melody very subtly, constantly shifting phrases through subtle chromatic changes, and the colors are flickering and blurred. Melody and accompaniment are in the same sound zone, the left and right hands are often intertwined, and the music fluctuates on the rippling water.
The theme reappears. At this time, the chord patterns of the right hand are no longer crowded in the narrow range, they span three octaves, and the melody of the left hand is played with an octave arpeggio, which is broad, elegant and full of emotion. Then the texture changed and the accompaniment was given to the left hand. It rises and falls magnificently with 32 notes, accompanied by dense chords. The melody of the right hand has a typical impressionist hazy color. Then the texture of music returned to the beginning, and the left hand played a new melody, and the atmosphere was a bit mysterious: its development mode was still the expansion of range and accompaniment sound type.