Topic 1: Dutch artist Piet Mondrian once said that “All painting – the painting of the past as well as of the present
shows us that its essential plastic means are only line and
color.” (Mondrian in Goldwater and Treves, 1945, 426-427)
How do you think this quote relates to the birth and
development of abstract art in the first half of the twentieth
century? Is it possible to provide just one definition of
abstraction? Using at least one example of abstract works
discussed in class, discuss the two questions above.

modernism is a 20th century movement

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 !