WILL MARK BRAINLIEST (not for school question) Theoretically, if I wrote every possible combination for a 4 note melody and chord progression, and then I went to write a new song with an 8 note melody, wouldn't I just be reusing two 4 note melodies I already used. And so forth, if I wrote a 16 note melody, would that just be four of the 4 note melodies already used, if all had been used up? And same question for chord progressions. Does this make the amount of piano pieces possible finite?

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 !