JulioHerrlein Posted December 30, 2017 Share Posted December 30, 2017 Parsimonious Voice Leading (again): attempts to provide an algorithm In a previous post I deleted, I was trying to find a good way to ensure the minimal parsimonious Voice-Leading (VL) between a sequence of chords. In this post I will try to explain my second attempt. Let's take a look at a sequence of chords, spreaded out almost in a random way, with no VL (setf chordstovl2 '(b3eb5g3 cs6e7gs3 b4f5g6 f7e5c2 d4f7e4 gs7e2a8) Let's specify and evaluate a variable for the number of voices used: (setf voices 3) Let's try to think the best way to connect this pitches with minimal movement. I will apply the following expression to ensure a better and less ambiguous result when applying the CHORD-CLOSEST-PATH function. Evaluate voices before (setf voices 3) Then (setf chordized (mclist (chordize-list (gen-divide voices (setf vlfinal (integer-to-pitch (modus (interval-to-pitch (replace-map '((-11 1) (-10 2) (-9 3) (-8 4) (-7 5) (7 -5) (8 -4) (9 -3)(10 -2)(11 -1)) (integer-to-interval (modus (pitch-to-midi (setf chordmelo (pitch-melodize chordstovl2)))))) :start (car chordmelo))))))))) Please note the use of the replace-map function ensuring that no movement will be greater than a tritone away. This means that a movement like "C to G" (7 semitones) will be convertet in a G to C (5 semitones). This ensure a modulo 12 (octave constraint) reduction of all the material and also a constraint in terms of the size of the movements that will not exceed 6 semitones. Finally, I will apply the CHORD-CLOSEST-PATH function (chord-closest-path (car chordized) (chordize-list (gen-divide voices vlfinal))) Hope it help some VL efforts. Best, Julio Herrlein Quote Link to comment Share on other sites More sharing options...
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