Phrasebox (midi filter)

Phrasebox seems to work largely by having patterns where notes are assigned on a piano roll to chord members (ex. 1-7). When a chord is played through phrasebox it will play that phrase but re-map it to whatever keys were part of the chord. For example if the input is C, D, F#, then the “1” is replaced with “C” and the “2” is replaced with “D” and the “3” is replaced with “F#.” There are also meta lines on the piano roll to select the highest note, lowest, etc.