It is the structure of the music.

One of the elements of Music.

He is a prominent musician of the impressionist movement, the focal point of other impressionist composers

It is a French movement during the late 19th and early 20th century that uses extensive colors and effects, ambiguous melodies, and innovative chords and progressions leading to slight dissonances.

Claude Debussy  is a prominent musician of the impressionist movement, the focal point of other impressionist composers

Arrange the different eras from early to a late period.