[peterburkimsher]

I talked about this with my friend Lenard, because I was confused why the Parsons code would be different for the same chord progression.

He then explained that I should move the key, and when I transposed the MIDI table, the Parsons codes all became the same.

I then asked him, is it possible to move up an octave for just one part of a chord progression? He said yes, it's possible, but people don't do that often. Normally people wait until the end of a chord progression to change octave.

[fenomas]

Talking about going up or down an octave here is just nomenclature. Musically speaking, changes in a chord progression don't go up or down - this is because roman numerals refer to pitch classes (like C, E, G), not to specific pitches (like C4, E5, G3).

The matter of which notes to play for a given chord is called "voicing", and it's orthogonal to anything mentioned in your article.