How does the "representation" of people, places, or events differ in romantic music and impressionist music?

s.  And the 20th Century has come up with a new tonal music that swept the world, with roots in Impressionism, folk and African music, and even a little Classical - namely, Jazz, Swing, Blues, and eventually, Rock.  

In the realm of symphonic music, the beginning of the 20th Century was a watershed time, when major composers were taking chromaticism (the slippery slope between keys) to extremes, mixing tone-colors so thickly it was blurring the lines of harmony, with the consequence of new works becoming bigger, but not really all that different - and every composers likes to feel "unique", for whatever reason.

i'm not sure i completely understand your question, but i will do my best.

i think the answer you are looking for is sequence. (see below)

a repeated melodic fragment would be best defined as repetition, while repeated chords (different or the same) could be a chord progression. however, you then mentioned the chord and melodic fragment beginning on higher or lower pitches, in that case, the answer could be best defined as a sequence. the definition of a sequence is as follows: "the restatement of a motif or longer melodic (or harmonic) passage at a higher or lower pitch in the same voice."

let me know if this !